How to banish a demon?

Hello, ever since I was about 12 (I'm now 14) I've been hearing a voice in my head claiming to be "Harvey". He makes me do things like cut myself and burn myself and when I refuse I hear a mixture between screaming and white noise in my head- REALLY loud. After I do them, he tells me he loves me and that it will all be better soon. My hands are shaking as I type this because I can hear it yelling at me not to. One time, I held a knife to my throat and threatend to kill myself unless it left me alone- he started screaming and my hands started twitching.
My question is, how can I banish "Harvey"?
Peace be with you
Thanks x

If you are having voices in your head telling you to harm yourself please get professional help.


http://www.mentalhealthamerica.net/