I want to kill myself, I am sick of being used and disrespected?

He talks down at me and tells me what to do. He comes to my flat every night and bangs on my windows and I try and ignore it and when I tell him I don't want him in he starts shouting at me. I feel powerless all the time and he makes me feel like cr*p. I don't know how to stand up for myself though and I have no friends. He gets really angry if I don't want to let him in. When he comes I feel like dirt and he uses all my coffee and everything and is always borrowing money off me. I am really considering suicide, I don't know what to do... I thought he was a friend but he just uses me. How do I get rid of him?