On Going...

My life seems so confusing, in turmoil, hell like right now. The intimidation and patronising is still on going and I've tried to not let it get to me but, its hard and I'm feeling so down in myself.
The person in question who is doing all the unpleasantness had stopped all his medication for Bipolar and last night he had picked a fight with someone and hurt him, then he drove round here early hours this morning stone drunk after a massive row with his wife and is making my life hell shouting at me and being unpleasant to me in the process. This person has always had a nasty side to him.
I literally dislike this person completely but, I don't know what to do to rid of him. He is so demanding with his intimidation's towards me. I really don't want anything to do with him. But, he says this is his house, he has always had a key to the front door. I asked for the key back when he first left here but he said this is his house although my name is the only name on the tenancy
Everything that goes wrong he says is my fault no matter what it is. I can't get rid of him and I'm afraid to do anything about it too. I feel suffocated by all of this, by this one person  who is causing all the unpleasantness.
 Sometimes he is a very nice person but his attitudes flare up at the least thing said or done. 
I go through the day when he is around not uttering a single word a lot of the time or all he gets from me is yes or no and a lot of times even that is the wrong answer.
I feel like I want to cry but, I won't. I also feel like I want to curl up and die right now to just to end it all.
Please God help me to stop this bad problem. I don't want anyone hurt or anything, just stop all of this nastyness that is around me. I don't know how to deal with it all. 

I know I shouldn't have written this but, this is my only outlet. I can't talk to anyone about this even when anyone asks me 'what is the matter' I can't tell anyone in fear of being hurt verbally or physically. I'm scared of the threats. I don't know if they are meant or just said to scare me. Which ever it is, it is working......I am a weak and scared person!