Is there a way to get my father out of my life? And/or any advice?

Im 17. Ever since i was just little, my dad has been an ***. He is an alcoholic and has a terrible gambling addiction, and i think he has bipolar disorder. Even when I was little, if i made the smallest mistake he would yell at me and cuss at me. In middle school I was extremely depressed, I barely had any friends and got picked on all the time, I stop trying in school and when my dad saw my grades he always freaked out, except he would yell for hours and hours week after week. He had no idea i was depressed or anything. Also, ever since i was in about 5th grade, my parents have fought alot. In the last 2 years, its become a daily thing, alot of the time I can't sleep at night because of it. He always tells me im a f***up and im never gonna be anything, I used to be nice to him, but, now when he asks me to help him with things I dont help. Ever since i was about 12 ive never been a happy person and in the last few months, ive been extremely depressed and was failing a bunch of classes so I asked my mom to let me go to a therapist and she made an appointment for a few weeks later. My dad never found out till 2 days before when we got a phone call from them and talked me out of going, then acted nice until the day after the appointment was supposed to be and now hes back to his old self. Ive told my mom to divorce him but she wont because she says it takes alot of time. Me and him have gotten in fist fights because of him being a dick and me standing up for myself. Hes unemployed and honestly has nothing to live for. Its terrible but ive had dreams where my dad died and afterwards everyone in the family is happier. Its so messed up but the time i spend with him is the time i resent the most, I no longer consider him my father anymore. How do i get him out of my life and.or any other advice?