I can't really cook, don't really clean and have trouble with self care. I have trouble with this even while stable. If something happens to my husband I would downsize to a small studio with not much stuff (for cleaning purposes). As for food/shopping I'd get it delivered from instacart on my good days. I would bulk shop for shelf stable foods. It's not the healthiest foods but it'll let me shop less often and have fast meals. If I had the money I would higher a cleaner 1-2x a month for the big things. If everything fails I would go into supportive housing.

She has to find solutions to her problems. She needs to work with her therapist to brainstorm solutions. If I were you I'd start saving and looking for a place. I would warn your mom that you are moving out in x months and stick to that. Even with all my limitations I would never want my son to feel he was stuck because of my limitations.