Sounds like life is difficult for you Quinn. Perhaps you could get an easy part-time job and just give her what you feel able to afford and say, "that's towards the bills". So rather than asking her for an amount, you decide what you can afford.
When my parents demanded money when I got my first job, they wanted everything I earned. It was unreasonable. I paid them half that. It's better for you to set the price than for her to demand what you cannot afford.
As for escape. I sympathise, but maybe a part-time job will give you confidence to find a way to build a life of your own. I have a story that you might find inspiring about a woman who lives in a van. It's a definite improvement on a car, and doesn't need to be expensive. Here's her story, if you're interested.
