I'm so sorry for what you're going through. I know exactly what you mean. I felt like my partner genuinely made me a worse person because the only way I could get him to do something and take responsibility was if I absolutely freaked out or gave ultimatums. It was almost like he was positively reinforcing me to become a monster. Over time my temper became shorter and shorter and I would snap at the most trivial things because asking nicely and nagging did absolutely nothing. My stress level was through the roof and I hated the person I'd become.

I don't have much advice for you but going on Lexapro helped, I stopped giving too many fucks about things and ironically our relationship is really stable now, because I rarely have no complaints regardless of the shitstorm that's around me. I read years ago on this sub that someone else also went on some SSRI and it "fixed" their relationship as well. I do not recommend this strategy but it's the only thing that's given me peace.