My mom has made me move 11 times and now she's making our family move again?

I'm going into the 11th grade next year and I've switched schools 11 times. Now my mom wants our family to move again, this time two hours away to Detroit. I really, really don't want to move. The only way I can stay at the school I go to now is if I live with my grandma, who is an alcoholic. I don't know what to do. I'm extremely depressed and ready to start cutting myself again, even though I haven't done it in a year. I don't want to leave behind my friends. And this year I take the ACT and the SAT. I really want to get into U of M Ann Arbor, and despite moving so often, I have the grades to get in. But Detroit schools aren't exactly the greatest, and I'm not sure if I'll be able to function well in my grandmother's home. What do I do?