I've been physically/mentally abused for 16 yrs. How do I get out of it?

For the past 16 years I've been abused. When I was 5 they beat me and my brother with a metal pipe for not being able to fall asleep. Everytime me and my brother would get into a little argument, they stuck needles in the palms of our hands. When my Dad went out of the country for family stuff, my mom beat the **** out of me because I wouldn't let her have her keys to go drinking. When I was a 4th grader, she didn't come home one night because she got caught for drunk driving. Any thing they could get their hands on, brooms, butcher knives, spatulas, scissors, etc. My mom even once threw a fan at my head. I am 16 now, a planned 3 year graduate from highschool, my GPA is above 3.8+, I am a good student, I have a good paying job. I don't ask my parents for anything. I am still getting abused. This morning I woke up with a really bad headache that I felt that I could not go to school. My mom jumped on me and started to choke and scratch me. I'm done with this shiit. I really am. They keep telling me to get the **** out of the house and that's what I'm planning on doing. I have a place to live with a friend who has a back house. My brother is planning on moving out with me also. He is 18. They are complete control freaks and everything has to be their way. I am scared that if I do move out and show them I am capable of living on my own without them and they have no more control over me, they will call the cops and say that I am a runaway. I have already started filling out emancipation papers, so in the meantime...what should I do? Should I just leave now? I can't stand abused by them anymore.