What should I do when someone's life is endangered?

My brother wants him dead cause I like this boy and my brother wants me to suffer. I tried commuting suicide, I lied to my brother, fought my brother, and tried to get over the boy I like. Nothing seems to be working. The boy will either be tortured or convinced into suicide if I don't do anything about. I really hate my family. My sister tries the same crap and his identity is kept secret from my parents. Everything would be so much better is my family died.