How Do I Break Up With Him?

My boyfriend loves me but I don't love him at all anymore. He proposed. I said no so he's mad. When I don't have time to spend with him he pouts and whines. It doesn't matter if I'm working or in cl he asks if those things are more important. I'm ashamed to go anywhere with him because he dresses like a bum. He argues with total strangers. I have to force him to get a haircut. I tell him when to shower. I don't want to be married to that. He claims to love when other men look at me but wants to fight if a man glances my way. He doesn't want to go back to school. He barely wants to work. His whole family is ghetto and do nothing but get welfare, deal drugs and smoke weed all day. He says I'm stuck up because I won't go visit his mother. Her house is filthy and infested with roaches. I won't let her ride in my car because roaches crawl out of her pockets and her purse. In the beginning he was different. He says he'll drive off a bridge if I break up. What should I do?