Abuse by single father on his male(17) child

I am a minor of 17 I will turn Major in 2 days(25sept). I have a abusive father who has been beating me under alcoholic substance for a long time now. My father who is a male (47) occupation: real-estate,has been divorced 2 times I am his first wife's son, who have been divorced for 12 years now I was in the custody of my father as I selected him at the age of 5 as he had a great influence on me as he bought me toys. My father is very controlling person he wants everything under his control(me as well),he has been abusing me for 2 years now by hitting me with my own guitar,one time he hit me with a cooker on my head,and he has also threatened me with knife and sharp objects which could be slash and stabed, he has also slashed me sometimes with this kind of objects. I took a notice of his behaviour that he is all good the whole day but only when he drinks he gets agressive and starts beating me with anything he finds. My father has a great influence in police and politics as he has connections due to his business conduct. I don't who my mother is and I don't have any relatives who can help me with stay, I cannot go to police as I know he can just do whatever he pleases there and abuse me more afterwards, I have tried many times to run before but I have to come back home eventually. I don't know what I can do as I have no hopes for the exicutive power and my only hope is judicial power of this system. Please help if possible