I'm so sorry to hear that you're in a situation like that.. I wish I knew more about how to help you.. but Idk how the system works in the US or wherever you are.. Are there any other social benefits you could apply for, and could you talk to a counsellor at school? Are there any children protective services that could help you? I think finding someone outside of family to talk to about this is a good idea... Like a teacher, someone else at school, or some other adult you feel comfortable with.. No teenagers should have to live like this.
I wonder if you could try to find a collective to stay at. Like a shared flat or something. It would require you having an income, though..
Keep posting here.. Maybe someone else here who knows the system better can give you some more suggestions.