Hi Paul,
Thanks for sharing. There are a few things I Would suggest, the first is to join the parents FB group where you will get a lot more responses from other parents.
If he has access to the computer, I would keep it to be a very limited amount of time - 1 hour max/day, not every day. You've seen a clear difference between him on the computer and him without it, and as hard as it is, him having less to no access is crucial for his health at this point.