It is time for a serious talk with your son. Give him some very concrete rules and the consequences when said rules are broken. If a consequence of any further violence is leaving home, do remember it doesn't have to be permanent but you do have to follow through.
How much importance does your son place on money? If so, you might try implementing a money jar for whenever he is rude to you or his brother, curses in the home, slams a door, whatever.
For my daughter, money is a big deal. For awhile, she was cursing constantly. I finally instituted a rule that every curse word said around me had a value since I was forced to hear language I truly did not like. Different words had different values. (For me, strangely enough, the F word was not as high on the list as God anything.) I heard a word and my money jar was immediately out for the fine. If the refused to pay, I refused to feed her or do anything whatsoever for her until all funds owed were paid. It took about 2 months, but she did stop the cursing and I ended up with a very lovely day at the spa.
Violence is another issue. That should not be tolerated even for a second. When my daughter was 18, she shoved me into a wall. She had been warned that the next time she touched me in anger she would be living elsewhere. I packed her stuff, helped her find a friend she could live with for a short while and took her over there. She stayed out of the house for 3 months. When she came back it was with the understanding that this was her last chance regarding violence. She has never raised her hand to me since.
So, decide what are appropriate behaviors that and what behaviors you want curtailed. Decide what you feel are appropriate consequences. Once you've done this, sit your not-so-dear son down and tell him (1) this is not a debate or discussion, (2) he is to sit and listen, (3) this is exactly what is going to happen from hereon and give him the new house rules and consequences, (4) if he doesn't like it, he can find somewhere new to live, (5) he has 24 hours to decide if he will follow your rules, (6) if he chooses not to, he has 48 hours to find a new place to live.
He's not going to change overnight but if he cares, he will make a true effort to follow your rules. Yes, he'll foul up at times and he'll argue and be mean but, hopefully, he'll quit some of his behavior, his violence will stop and you'll be a little less fearful in your own home. It won't be easy, but it is doable.