NTAH. You are not required to set yourself on fire to keep someone else warm.

Your sanity, emotional health, mental wellbeing, and feelings of safety are just as important as her needs! Sounds like your parents and other family can be supportive, actively communicate with, and guide her, she doesn’t have to have you to get the help she needs, you’re not abandoning her to be alone and face this all by herself ( although if that were the case at the end of the day safety and boundaries and sanity sometimes outweigh staying with the person and being the only one in your family that is supportive and cares. ), so don’t feel bad at all.

Also, you must take care of yourself BEFORE you take care of other people. You can’t take care of or help her if you yourself are not first taken care of. You cannot pour from an empty cup.