It's not that I can't. The problem is that when I'm with someone, I deeply yearn to be alone. I'd love to have my life for myself, with no responsibility with no one else - just me.
But then, when I'm alone, I feel like a failure, like I need a relationship to feel complete, and I fucking hate that. So I end up in another relationship, and after two years I can't stand it anymore, and the cycle repeats.
What the hell. Has anyone suffered from something like that? How can you be alone and not feel lonely? How to kill this need to be with someone?
EDIT: Thanks for all the answers, I'm taking every single one into consideration. Please, keep them coming.
I'm a person who needs a lot of alone time. It took me a while to learn how to set boundaries with partners. That balance wasn't easy for me to find. Do you feel like it would benefit you if you got more alone time in your existing relationships?
I think so, yes, but then my girlfriend likes to be around and is really upset when I ask to be alone. She's not wrong thought, because if left by myself I can disappear for a long time...
What does upset mean? Its a bit different if she's concerned for you vs if she can't be alone. My wife was concerned for me when I was playing Minecraft until 4am every night during a stressful time in my life. She can't be alone when she's in my office during the middle of the workday telling me ten different YouTuber's life stories. :D
I hope you find the balance that you're looking for. If your girlfriend feels more social than you, its not necessarily bad to have her call her friends or something. I regularly tell my wife to "call Susan" or something like that when she wants to talk about something that I don't have any bandwidth for or interest in. As long as you make an effort to connect when you can and don't neglect her, I think it's a fair ask.