I didn't know how to remove myself from abuse properly and couldn't begin to until I started to learn some of those 'drastic' things that actually aren't that drastic. They just seem like it from inside a situation. Because of the abuse you are used to being around, you've been kept from learning them, because it would allow you to successfully leave. It is a common tactic, and treating it like it is your job to learn this stuff now will save you a lot of problems down the road. Start doing things now. Work on how to leave before she dies so it won't be much of a complication after.

Never take care of people who have abused you, even if they never admit to the bad parenting, manipulation and abuse. You just repress the abuse and will probably need some help to function and recover from the abuse you went through, and the dysfunctional dynamics you were taught. NEVER have ANYTHING to do with people who affiliate with people who try to force abusive families to stay together, or associate with those abusive family members. I probably will never want to have children because of how fucked up the people who were responsible for my care failed me. I am of the very solid belief that people who have children who cannot teach, care for or protect them should be punished, and their children should be separated from them as young as possible, so they can get out properly on their own, recover from the mistakes of bad parenting, and not be punished for things they never understood due to those failures.

You will probably need some help figuring out how to function better on your own, outside of this. You've been held back and should not feel a shred of guilt for basically leaving this person to die. Is this harsh? Absolutely. Do I speak from experience in understanding people who have had to survive life circumstances of shitty parents who treat the children they never properly cared for like they were their pets? Yes, unfortunately. You need to learn how to start being politely, quietly, yet ruthlessly selfish for yourself. It is one of the few ways to break that abuse cye dynamic that families who have children when they shouldn't tend to create.