I see that you went from abusive boyfriend straight to abusive brother.

Not sure how can they “not allow” a grown woman to eat in a different room. What are they going to do? Call the police on you?

Are you on disability? If yes you might be better off going to a homeless shelter and that would expedite you getting into some type of subsidized housing. If you aren’t disabled, then work later hours. Don’t be home when they eat. If you are trying to move out, you’ll need to save money. So get a second job. Don’t be home.

The reasonable rules for adult relatives are to not be loud and not make a mess. All other made up rules are bogus

You spent two decades pleasing a man who lived double life and abused you. You don’t need to spend another minute being abused by anybody.