Is it normal to feel murderous

Lately, I have been wanting to end a fellow persons life. It started out as a friendship status, but I wanted more with him, I wanted to be loved as a gay couple. After he broke away from me (from gang afflictions) he started to hate me for no reason. This made me crazy. Now I am known as that 20 year old crazy person. I want to kill him and rape him. Earlier today I was walking in town and saw him alone on a backstreet. He ran as fast as he could, but I caught up wearing my trench coat with a hunting knife in hand. He than pulled a cell phone out while running and called someone. This made me stop in my tracks and ask myself what I would do with his body. I walked away and found myself cutting my arm in x-shapes. What to do now...