I'm sort of in similar situation with my family. Except unlike you, I decided to "move out on my own" like back in the days. My family situation wasn't quite as difficult, but in my opinion, still intolerable.
So anyway, I'm 19 and I moved out over a year ago, thinking I would just start my adult life, whatever it takes. Of course, my parents refused to pay for school, so I took the year off. Then when I tried going back this fall as an in-state student, they told me I needed financial independence. I told them I was, but they checked my taxes, and it turned out my family was still claiming me as a dependent, even though I lived on the other side of the country with no financial support. So I contacted my family and threatened to sue if they didn't refile their taxes. That took months to straighten out, but eventually did. Turned out I needed two years of independence though, so now I have to wait another year...
I wanted to go back to school, so i said f-that. I've decided to pay triple the cost for out-of-state, figuring I can get loans. NOPE. So, in order to filie my FAFSA I need my parents financial information for the expected family contribution. Of course, my parents do make a fair amount of money, even if they won't give me a dime. Even though I'm independent according to the government, I'm not according to the US public school system. You're only independent if you have a bachelors or are over 26. So, despite fighting for the better part of a year for independence, I'm not. And now they expect my family to pay 18k for my education... which is more than tuition costs... which makes my loan prospects quite slim.
So bottom line is that even though I tried to be responsible for myself, and not hurt my family, it didn't matter. Society no longer is set up so that kids can move out and become adults at a young age. You're all but forced to depend on your parents anyway. It sucks that things aren't easy for you, and I truly emphasize. Get your parents to pay for it. They should, and its not fair that you should have to anyway. Once you have your degree, life will be easier, you can get a good job, leave your family behind and start your life on your own. Good luck!