Well, we parents usually do what we do because we love our children and want them to stop, but I think it's time to stop trying to cushion his fall. Let him detox at a proper detox, do not get him pills...do you realize YOU could have been arrested and have a record for that? (and I say that as kindly as I can).
His detox, his plan, his recovery...or not. All you need to figure out is what your boundaries are about him living at home.
And...let him go without a computer. He sold it for drugs, his consequence to live with.
The founder of SoberRecovery, a recovering addict himself, once told me that I just might love my son right into the grave. That jolted me but it was true and it gave me a healthier perspective of the harm I was doing, thinking it would save my son. Nothing we do or don't do will save them, only they can do that when they are ready. If love could safe our addicted love ones, not one of us would be here.
So have him write up his recovery plan and commit to it. And let him do it all by himself.
Hugs