I'm constantly anxious and depressed, and there seems no way out for me, what do I do?

I’m twenty-one, and I’ve only recently finished school. About a year back my mum and dad had a nasty separation and my little sister now lives with my mum. My younger brother and I live with my dad and we hardly speak to our sister because my mum doesn’t let her call or visit us.
My mum has always been abusive and fanatical, especially to me because I was the eldest and she’d say I was like my dad. When I was eleven my dad left to work abroad and we were withdrawn from school. Since then we’ve spent our lives at home—it was painful and lonely and more like a prison. My mum would belt my brother and me, make me kneel down for hours to punish me and say things that just broke me down completely and I had no place to run or hide because we hardly knew any relatives. My dad returned after nine years to realize that we were not in school and mum had spent all the money he’d been sending without saving anything.
Now my dad and brother work, my dad works nights and my brother in the evenings and I’m always at home. I tried to work back when my dad had just returned and my mum and sister were living with us, but everyday there’d be fights and things broken in the house it was hard to concentrate at work.
My dad tries to listen to me but I can hardly communicate anymore because he cuts me short and says I’m blaming him for what my mother did. I’m still studying though I don’t even know if I’ll complete college this year and I’m tired of staying at home, but my dad won’t let me find a job that suits me, he wants me to take something close by so I can walk to work and that’s quite impossible. There are days when I have hope and I feel like I don’t have it that bad for me, I know worse things happen to people. And then there are days when I don’t want to go on anymore, because I’m like an emotional hostage.
I’m not allowed to have friends. I never had a cell phone till it was my brother’s idea to get me one for my twenty-first birthday, but I’m not allowed to give my cell phone number to anyone because my dad says it’s only meant for my brother and him to stay in touch with me in case of emergency. My dad says he can help me develop confidence in myself and that I should give an eff about people or this world, I shouldn’t be worldly; I think I’d have been happier in a convent full of nuns at least I would have made a decision for myself.
I met a friend in church eight months ago, because of that my dad doesn’t let me go to church anymore though we’ve been in touch and my dad says I’m stupid and boy crazy when I asked him if I could just go out with the guy for one day. He says I’ll give our family a bad name roaming around with boys. I’m a woman and it’s just one guy!
I’m trying hard to cope with depression, uncontrollable crying spells and anxiety and it feels life’s passing away so fast I’ll be an old maid soon. Am I just being difficult, like my dad says, or do I need to just wrench control of my life and forget about all the consequences?