Temper Tantrums, dope smoking, Drinking, and sex in my house

I have a 19 year old son, who's been out of High School for a year, tried going to a Jr. College near by, decided to drop out at his dads request, and was supposed to get a job working for the company his dad is working for, but the job never came true, my son has been drinking and smoking pot everyday since this, he has sex in my house with his 17 year old girlfriend when every he feels like it, When I try to stop it he pushes and shoves me around sometimes leaving bruises on my wrist and upper arms, his dads no help, he drinks everyday has well, they sit out side in the afternoon up till dark drinking, getting into arguments, which turn into nearly fights. I want to call the cops on him, but he threatens to hurt me are put more holes into my walls at the house, and when he gets out he says he will really hurt me for calling the cops on him, my husband will not help with this matter at all, it's like all he's concerned about is being his buddy, instead of helping him. Please what can I do, where can I get help?