advice needed

My 11 yr old son lives where there are no neighbors to play with and I, his dad, have little free time to spend with him. He's never showed much interest in anything other than dinosaurs for a year. Now all he wants to do is play Minecraft and watch youtube videos about it. I keep trying to limit him to 2 hours a day (which his mom often opposes since he's "bored") but am thinking about selling his laptop. Tonight I tried doing a mathematics overview with him but his mind was so buzzing with "electronic" activity he couldn't even add 9 plus 7. really. So I stormed in to his mothers room (my ex) and said that he was completely restricted from using the computer till after he takes his exams in a few days. Then I need to decide what to do. Please vote:
A. limit him to 2 hours daily
B. sell the computer

ps- we live in one of the hottest countries in the world and we are in the middle of a 6 month long summer and so "playing outside" is not an option. Sometimes we pretend to play tennis right as the sun is going down and wind up drenched in sweat.
I've bought him remote control helicopters and a car but they didn't much interest him. Last report card he basically got the lowest score possible in 4 of 6 classes. I feel so guilty for buying the laptop for him and the anguish he will have if/when I sell it. If he keeps it then I am guilty of allowing this destructive addiction. If I get rid of it then I'm guilty of selling the only thing he's ever loved 9other than the dog he used to have). I'm F'd Tweet