I don't think that any of us ought to automatically jump to the conclusion that the OP basically dropped the ball parenting her son. Parenting an aspie child isn't always easy, and trying to force them to do anything that they don't want to do, or see the value of doing is almost impossible. There are many of us that refused to go to school at about that age. For me, that's when school became too much to bare, and there wasn't a thing anyone could've done to make me go.
I hate to say it, but i agree with the other posters that said that you may have to pull the computer time. Normally, I don't suggest withholding special interests, because that just seems so cruel, however you may have no other choice. I don't think that I'd take it completely away, nor do i think that I'd force him to work to pay for it as of yet. Is there any specialists nearby that deal with ASD? If so, I'd make a deal with him that he can have x amount of computer time if he will participate in therapy. His obsession with animae may be so strong that he may not be able to just stop with simple willpower. Those kinds of things can become like addictions. It's obvious that he needs some sort of help to live a more balanced life, whether that be working a full-time job or not really depends on the individual. Some on the spectrum can't do that, but he does need to learn some life skills. I would just hate for people to jump to the conclusion that he's lazy, when it's possible that he can't do what the world asks of him. Everybody is impaired, and enhanced differently in regards to their AS.