I wish you all the luck in the world, blahblah. I'll tell you a secret, well, sort of. I see your posts and I wonder why I couldn't find somebody like you and I had to find my xH. I've read you fight, try to understand, to accomodate, to pretzel yourself, to do whatever you can to keep going. You kept the dream alive when she was better, you tried, you really tried with all your might. If you can't anymore, it's not because you didn't try, and that honors you. You are a good person, and deserve happiness.
I wish you have all the strengh you need to carry on with your decision. That your empathy and love don't get in the way. She is suffering for sure and that is horrible. It would be so much better if somehow you could spare her, and YOU, this pain. But you know now that you can't, unless you sacrifice yourself.
I'll keep you in my thoughts tonight, my friend. That your next steps are steady, that you can sleep at night, that the pain leaves you soon.