Help! Mother wants to keep me at home like Rapunzel

Hai, I'm 15 and currently in 10th grade. My mother is abusive and she's extremly controlling. She hits me, calls me useless, rotten, ugly, and yells at me for every little thing, she won't even let me choose what to wear. She says she loves me but she only ever shows it when her friends and family are around. I thought I could finally be free once I get to university and be an adult but now she's saying I have to stay with her until she can 'pass me on' to a rich husband who will also live closeby so she can stay close to me. "You have a duty to me, I gave birth to you and payed for your blah," she says. My best friend and I have been planning to study abroad in Canada for the past year and we've done so much work to get there, I've even learnt french! Of course I was expecting them to pay for at least tuition, but both my parents are completely against it. My mother told me I didn't need to study in Canada or anywhere else because she'd provide for me for the rest of my life! The moment I heard that i freaked out, I don't want her choosing which rich guy I marry and picking my clothes at 30! I tried reasoning with my father and the rest of my family but my mother had brainwashed all of them into thinking I'm incapable of doing anything for myself. She's also using my autoimmune disease (I have lupus) and "you're a girl" as an excuse. I'm afraid if I don't study abroad for university I'll never have another chance to live my own life. She'll just continue making all of the decisions in my life as well as my children's if I ever have any. I tried making money on my own but I can only get so far at this age. I've gathered C$4000 so far, and although it's nearly impossible to pay for tuition I still had hope. Now that hope is crushed, my parents had found out I was working to study abroad and they forbade me from making anymore money. I feel so sad and empty, it feels like I lost my life purpose. I don't want to give up but I don't know what to do, any advice? Also please don't say things like "call child services" or "talk to an adult you trust," it doesn't work like that here. I live in a country where parents practically own their children, abuse isn't chargeable so never mind that. Thankyou in advance, sorry for the long thread!