It's by design. Almost all blankets have polyester or some synthetics. It's basically like sleeping under plastic bottles. Excellent for heat retention. Absolutely shit for heat regulation.
Pure cotton is better, but not as ideal as wool. Your life will change under a wool blanket. Wool blankets are insanely expensive, but you can find utility wool blankets for pretty cheap (very scratchy), you just have to sandwich them between some thin layers so you don't feel the scratchiness. You can layer them multiple times and it is very difficult to have too many as they breathe very well.
Wool filled comforters with a cotton shell is the answer to this. $100-$200. So comfy. Machine washable. 100% breathable, sweat wicking, heavy and comforting.
I am a very peculiar sleeper. It needs to be fairly cold (63°F is ideal), with a fan blowing directly on me for cooling and noise, with a chunky weighted blanket on top of a linen sheet that allows the fan air through, one pillow between my knees and a king length pillow on both sides, then my head is sandwiched between two more pillows, with an eye mask on and noise canceling headphones to make the fan sound far away.
But I sleep like a baby under these conditions as long as I've taken my melatonin.
Fortunately it's the latter. I'm a lucky man in that regard. But he did have a lot of trouble adjusting when we started dating.
We disagree on our bed firmness. I had to buy a custom sized mattress topper that covers his half of the bed and is firm and cut the soft one I had in half to cover my side.
I'm 41 and figured this fully out maybe 3 years ago...
I had terrible insomnia when I was a kid, so sleep had always been something I was chasing. I also forgot to mention that I need a king sized bed, California King is preferred, but I'm 6'4" so that is more a factor of fit than comfort.
Well I do miss trazodone, but it stopped working for me when I was taking it regularly. Never tried doxylamine, but for a while I was on mirtazapine and diphenhydramine for the sleep side effects only.
But I weened myself off them after reading they can cause dementia if taken for a prolonged period. A decade doesn't count as prolonged, does it? Eh, I'll be fine I'm sure.
Raising the temperature of the room to 19 fixed this, because then when it's warm my body naturally throws a leg out or removes some blanket, which it refuses to do when the room is too cold. As much as I like sleeping in the cold with a big blanket, now i can sleep and not wake up in a wet bed.