teenagers, computers and violence

I am a mum to a 14 year old son with Asperger Syndrome. He is now bigger than me and makes no attempt to contorol his anger. He is a very bright boy and a wonderfully gifted musician but all he does day and night is play on his computer. He is happy to stay up all night and gets in a rage when we try and make him go to bed. If we try and get him to do anything other than play on the computer then he just errupts into fury and starts hitting us and damaging property.

He is on fluoxetin and manages well at school with a high level of support. I don't want to give up on him but I'm at my wit's end.

I am a special teacher and can give sound, sensible advice to other parents but it just doesn't seem to work for me.

HELP!