I think I understand how you feel. It's difficult and confusing and I'm sorry you feel like that. I think you might feel like I do about my husband. I absolutely adore and love him more than anything in this world, and part of me wants to get better for him. But most of the time... I still feel a profound sadness in my chest that i cant explain and wont go away. I know that if it weren't for him and my dog, I'd have absolutely no desire to exist at all. I have a severe cognitive dissonance; I want to spend every moment for forever with my husband, and I also want to end my pain and hurt inside that refuses to leave me alone.
I think I read in a self help/psychology book that to truly get better, you have to get better for yourself and not others. But I also read that absolutely any reason to keep trying to live and get better is a valid reason to continue. Even if it's just to water the damn plants or see who wins the next superbowl. It said that even if your path to getting better starts off as being for someone else, if you want to stick with it and keep trying, you will eventually start doing it for yourself.
I wasn't trying to push toxic positivity, just something I've read. I have no real solution or advice, but I want to say that your not alone and I'm sorry you feel that way too. I hope you find peace.