Do you have a mantra that keeps you going through tough times?

This too shall pass
- Me: This too shall pass
  My circumstances: YOU SHALL NOT PASS
  
  And it’s true. We don’t survive the trials of life we just molt into the next version of ourselves.
  If a certain transformation is going un-completed because it feels like death, it can be helpful to recognize that it is death. That’s no illusion.
  To truly live life to the fullest, one has to sacrifice their self to a future person again and again and again. When you finally get there, it won’t be as the person you are now.
- IRS agent: You have thousands of dollars of overdue taxes
  Me: This too shall pass
  
  With enough time it will.
  Source: my wife works for a tax authority
  
  Reminds me of Louis CK’s joke about suicide.
  You get a letter from the DMV: “You have to appear at such and such …”
  “No I don’t”
- Like a kidney stone
- This has been my motto for years but now I have incurable cancer in the brain so I'm looking for a new one...
  
  Will happen. Happening. Happened.
  
  So what is it that you intend to do before you lose the capacity to do things?

Just the fuckin way she goes boys
- Trailer park boys, full of insight
- So we were all gonna have a good time and get drunk but now all the money’s gone into the VLTs so there’s no drinkin or gettin drunk or nothing is … how she goes, apparently
- Sometimes she goes, sometimes she doesn't... Fuckin way she goes...
- Fuck you mean it's just the fuckin way she goes?

Don't know if it counts, but I often think about
when I face difficult situations.

"You’ll feel better in the morning."
I get a lot of intrusive, negative, catastrophising thoughts late at night. Worrying about things I would never worry about during daylight.
I always try to tell myself: don't think about this stuff right now, it's not helpful. Put it aside and if it still feels important in the morning then you can do something about it. Fixating on it right now serves no useful purpose.

"I wish it need not have happened in my time," said Frodo. "So do I," said Gandalf, "and so do all who live to see such times. But that is not for them to decide. All we have to decide is what to do with the time that is given us." J.R.R. Tolkien, The Fellowship of the Ring
This resonated a lot with me during the pandemic shutdown.

"This too will pass"
True for both good and bad times. Good time? Enjoy it, since it will pass. Bad time? Endure it, it will pass.
- I like its variant better: "This too shall pass."
- https://youtu.be/Tg5kB4UcAuA

That didn't work... Next!
And when it's a real big mess: In 100 years, nobody will know or care.
- Yup, a big factor is realising that none of this actually matters.
  
  Depending on the OPs circumstances, that realization may actually be what is causing them their bad times.
  Friend of mine has had ideation for a long ass time and the frequency of them trying to step out of life increased considerably when that realization hit them.
  When you're already feeling worthless and without purpose, realizing nothing has purpose and this whole concept of life and living we have is utterly meaningless in the grand scale of the universe, it's not ideal.
  
  It does but it won’t so just be patient
- Just imagine that one person in Europe about 30,000 years ago who found himself stuck in some hole in the ground, alone and broken, finally dying of thirst and infection, who left behind four kids and his bonded life partner. They didn’t know where he went, and in only a season she had paired with another mate in the clan. Within four years anything said about this man had wilted to almost never, and forget about anything having been written down or logged in any way.
  Forgotten to time.
  It didn’t take long then. Might take longer now. But time will still forget us all. Make your mark while you’re around, because after that no one will give a shit.

Shit piss cunt cocksucker shits fart dirty twat

"Slow down for a moment, tackle one thing at a time" helps a lot when I'm anxious and overwhelmed.
- Yup. One thing at a time is a powerful thing.
  When I was in college I had a therapist. I was telling him how I wasn’t sure if I was being perfectly efficient about how I was going about things, that I was wasting time and energy in my approach.
  His advice was just to focus on doing something rather than nothing, without trying to optimize it.
  It really helped.
- This is really close to what I do as well. If I’m overwhelmed, I think to myself, “Just start with one small thing. Then do another small thing. Eventually, lots of small things add up to a large thing. Won’t get anywhere doing nothing and worrying about how much I have to do.”

"One day at a time. One hour at a time. Let's just get through this one little task."

The way out is through.
- Days of thunder?
  
  I've actually never seen it, but I might just watch it this weekend.

It's what it's. My butchering of it is what it is
- It's'wh't's
  
  Would that't'were so simple.
  
  It''''s

It’ll sound cheesy, but “Don’t Go Hollow” is that phrase for me.
In 2019, I was hospitalized for suicidal ideation. When at in-patient, we didn’t get much to express ourselves. Every meal, we ate with plastic utensils and foam plates and cups for safety. I would carve that phrase into the cups, along with a bonfire.
“Don’t Go Hollow” goes back to Dark Souls. It’s a phrase that means something in the game world, but it’s also metaphorical. What’s an avatar without the player? It’s like a body without spirit. You’re not progressing in the game because you checked out. If you want to keep going, you need to be present, to keep trying.
Other ones that come to mind are “This is a moment. It will pass.” which I said in the showers that scared the fuck out of me, and “Fall down 7 times, get up 8.” “Let it rip,” from the Bear is another one I like.

"I am here, I move forward." Might do for you. Say it, take the time to see where you are and what you can do next. Even a small improvement is valid, just make sure you move and don't dwell on things you can't control.
Best of luck.

”I can kill myself tomorrow."
Sometimes it means one thing, sometimes another.

My personal favorite is from Wheel of Time
"Almost dead yesterday, maybe dead tomorrow, but alive gloriously alive today"
Another good one from the same series is "We are always more afraid than we wish to be, but we can always be braver than we expect."

The whole book of Ecclesiastes

There is neither happiness nor unhappiness in this world; there is only the comparison of one state with another. Only a man who has felt ultimate despair is capable of feeling ultimate bliss. It is necessary to have wished for death in order to know how good it is to live.....the sum of all human wisdom will be contained in these two words: Wait and Hope.
Alexandre Dumas, The Count of Monte Cristo

This is probably a toxic one I learned from my teachers that time I tried learning Korean:
If it feels like you're drowning it's cause you haven't died yet.
- Damn Korean’s hard core

In the future this will be a period of time I'll remember clearly, which makes it valuable. Easy times lead to no substantial memories which is effectively the loss of that time.
- This is how I interact with my dad’s dog.
  Dad’s out of town so I’m staying at his house taking care of his dog. I love this dog. But also take this dog for granted a lot, especially when I’ve just come home from work and I’m irritable and overwhelmed.
  I pretend that, instead of this being me here and now, it’s a future version of me, from maybe thirty years in the future, when this dog has been long dead. Then I imagine that this moment is some kind of miracle wormhole through time where the me from the time this dog is an ancient memory has been given a few minutes to be with the dog.
  Like, I would happily trade my finger and all the money I have for a minute with my mother, who died fifteen years ago. But I can’t.
  What I can do is treat the people around me as I would treat my mother in that one minute, if it were somehow granted to me.
  Almost like opening myself up to visitation from my future self. And in doing so, I experience more richly and it will actually work. When the dog is long gone, in the ground for decades, I will be able to visit him because I opened myself, which led to deep memory inscription.
  
  Brilliant post, and I try to do the same thing, if I'm somewhere beautiful or profound and I have a few minutes to myself I like to make a "memory bubble" to me it's like a little snapshot of experience that I work really hard to recall every minute detail ( including my emotional state and sounds and smells, etc..) and then I can revisit them in the future.
  I like this because it makes you appreciate where you are at the time more, and gives you good memories to lean on in the future.
- Easy times lead to no substantial memories
  This seems wrong
  
  I'm open to discussion, but now that I've existed for a substantial period of time, I've found that my most prevailing memories are the ones hard won (e.g. when I almost had to sleep on the streets or ran out of money in a foreign country or got evicted from my flat). Whereas days sat on my couch watching telly, or in the pub having fun with friends, or another routine day in the gym are all blurred memories with no definition and no real sense of elapsed time.

"it's okay, just keep swimming". That's really what i always tell myself.

I gatekeep my own misery with perspective.
Knowing that there's billions of people having a far worse moment/day/life keeps me intact. I have nothing to complain about.
- This one has never helped me. It just has me wanting to give up so much more, overwhelmed by the pain and suffering of others along with my own.
  
  This divergent response may have something to do with personality types.

"Whatever happens, happens."
Spike Spiegel, Cowboy Bebop.
It is a space anime with characters living quick and dangerous, but due to the way it is written, hand-animated, detailed, and grounded to a heavy extent, this one anime hits different as I age. It is itself targeting an older audience compared other blockbuster animes, but nevertheless it is one that keeps some aspects with you through the rewatches, but can also have substantial new feelings as you gain different life experiences. All of the main characters themselves have some kind of a past that is weighing them down through their current affairs, but their power to go on can be mostly summarized to living a life in limbo all the while trying to cope with it via simple tough-guy acts of trying to be indifferent to it.
It is not a good mantra that can be maintained for long. It is rather something that helps delaying the immediate feelings before the acceptance comes.

🎵Just keep swimming, just keep swimming🎶

Not really a mantra, but I try to remind myself that the only thing that seems to be certain in life is change. If you're in a shitty spot, just wait for the change. Will it be a change for the good or a change for the bad? You can't always predict it, but it WILL change. Often, that means when I'm in a shitty mood or scenario, I wait for the change to happen in a more positive direction.

"Nothing changes if nothing changes"

My mantra is just rama rama rama. Meditation with a mantra helps a lot of you put in the work beforehand.
It sounds like you're talking more about a motivational slogan, though. Mine is, "You don't have to want it, you just have to do it." It helps because it frees me from the tyranny of desire. I don't need to figure out if I'm in the mood. I don't need to trick myself into enjoying it. I can just do the thing and be done with it.
Relatedly, there's a line from a favorite book, "Somebody has to and no one else will" with a similar vibe.
- In my case it’s a mantra, because I say it out loud repeatedly.

I say "fuck this" or "fuck that" or "fuck it all" or "fuck everything" pretty often. I guess that?

My dad always said "Always do the right thing", and "the world is what you make of it"

"If you're going through hell, keep going" -Winston Churchill

I don't have one, but these replies remind me of some lines from Inglourious Basterds:
"You'll be hanged for this!"
"No, I'll get chewed out. I've been chewed out before."

Fate is inescapable to both protagonists as antagonists. Death remains the great equalizer across all layers of society.
- I'm not sure how "Your choices don't matter and you'll all die anyway." is supposed to keep people going, but okay.
  
  A lot of us are more worried about making wrong choices than we should be.
  
  YMMV but to me it's a comforting thought that, in the very end, nothing you do actually matters. From the most insignificant pauper to Musk, eventually we all die, rot, fade away and are forgotten.
  That may be sad, but it liberates you in this moment. It does for me somewhat, anyway.

Fall down seven times, stand up eight times.

Go through the pain, as it is the way
Once you went through it and the pain is no more, you'll have a whole new range of possible that were masked by the pain beforehand.
Don't die tho
- "Fear is the mind-killer" comes to mind here.
  
  Yes but it's more about letting go through it than fighting it

When I was young life was pure chaos. It was a constant battle and I often looked for things that would ground me and let my mind rest for a bit. I discovered the Peter Gabriel song Washing of the Water. I really liked how he sang it and so I memorized the words. They are good and when its a very dark time for me, the words are a great way for me to gain a little mental peace.
The whole song is beautiful. The perfect balance of wanting calm in hard times and finding peace in the nature of things https://piped.video/watch?v=Ic4N6rT6Qks

"Tough times never last, only tough people last. alien translation" youtube

Hakuna matata!
- What a wonderful phrase!

Ah well, nothing to be done about it, might as well carry on

If you are going through some shit, keep going.

"If you are going through hell, keep going". Churchill

It’s got to be true and uplifting.
One of the most effective for me has been “I can make my life a little better today”.
I just keep repeating that when I have nothing in the tank, and it helps me find a little more.

Worse things have happened to better people.

"It's only a gameshow". Big Brother contestants sang it to themselves on one of the seasons back in the 00s. My colleagues and I did the same during a rough patch at a former company I worked for.
I like it because it's a reminder that things can seem immovably important until you remove yourself from the context of that situation and assess it from the outside.

"I'm working on it." when I feel like things are where I want them to be, but they're gradually getting there, it makes it seem okay, since I'm actively working towards a goal. This could be my weightloss, managing my depression, cleaning the house, or going through endless emails. It helps to know that it's fine that it's not perfect or great yet, but I'm working on it.

swearing like an injured sailor under my breath

I can't go on. I'll go on.
(Samuel Beckett)

I made it through 100% of all the bad days, weeks and months in my life so far. I will also make it through the ones that have yet to come.
...and on my more cynical days, this follow-up:
And if, one day, I won't survive a bad day, then it is not my f[%$]ng problem anymore.
I tried to have a more positive mantra, but eventually realized that sheer spite can be a powerful motivator in bad times, even more so than trying to stay "nice" to the rest of the world.
- Kant approves.
- Anger is a really powerful motivator. I spent years of my life trying to shut down my anger from childhood. I had such a violent temper up to my mid-20s. Now I'm 40 and in a complete "dead-zone". No motivation, no drive.
  I've found I get most motivated when one of two things happen - I forget to take my anti-depressant for the day or I try to quit vaping. Both these things cause me to get irritable and both cause me to shift and do something.
  P.S. Meth also motivates me but that's not a long-term strategy worth pursuing as I'm trying to remain sober.

Despite all my rage I'm still just a rat in a cage.

From Lord of the Rings: "Not all who wander are lost."
From the Old Kingdom Series: "Does the walker choose the path, or does the path choose the walker?"
- I like the idea and message of the first one except that I used to have an absolute asshole of a neighbor who drove a heep-ed out Wrangler with a spare tire cover which had the phrase on it. I can't separate any longer.

Don't worry about things you can't change.

The closest I come is "Calgon, take me away."
- Ancient Chinese secret, eh? ;)
  
  What do you mean?

shrug shoulders
Eh…
I don’t have the vocabulary for a good mantra like most of you. But a shoulder shrug and a “what are you gonna do about it” kind of noise is enough for me.