Harassment and blackmail by 14 year old son

My son is 14 year old, he is completely out of track.. he stopped going to school from his 7th standard stole around 60k from home and spent on friends, liquor, cigarettes, weed when caught and asked him he was so aggressive and literally started hitting me and his mother with a belt and what not.. after so much struggle we managed to join him in a rehab he stayed there for 1year and came back home. Things were fine for a week and after that everything cameback to square one recent he started blackmailing me and threatening me for everything i am helpless and started surrendering to him by giving him whatever he wants.. recently he started abusing me hitting me punching me. I am helpless I can’t choose anything.. i am afraid if i join him in a rehab he might come back and kill me.. i want to get rid of him. I can’t find a way. I am extremely disturbed, depressed and blank. How do i proceed?