How do you get rid of an online leeche?

This person has been at it for 4years. He has something against me. He is a gay african american. Deeplyes insecure. Sometimes he becomes a troll and people continue to feed him not knowing he is a leeche. I'm a young african american girl. This leeche tries to take advantage of me. He tell lies to continue to leeche off me. I'm kind of helpless here.