Please help me, I have a real problem. I'm a bully.

I know how much it hurts people, but I enjoy doing it and I feel terrible doing it at the same time. From recent events, I think I may even be developing depression myself. I've lost my interest in my hobbies already. I feel like harming myself because of how terrible I am. I don't know what to do.. just share your bullying story with me, give me advice or something. I need help. I really need it. I'm almost crying for help.