Hate My Brother. Help.?

I don't do anything to make him mad, he just verbally abuses me until I want to kill myself. I'm hoping to reach a resolution soon, otherwise I may end up actually doing it. He calls me gay every few minutes (not exaggerating) and constantly makes fun of me. He considers himself a "troll" because he can make people angry, but he doesn't know when to stop himself. I've tried calmly and peacefully asking him to stop, but he refuses. I've told my parents, and they threaten to punish him but they never do. We used to get along fairly well, but now we just don't. I've tried everything to keep him from taunting me, but nothing has worked so far. He's told me that he's "just joking" and to "lighten up", but calling me a ****** over and over and making me angry for his own amusement isn't joking to me. I'm begging at this point, someone please tell me how I can make him stop. He makes me want to kill myself violently.