Kingz is right about one of you needing to break the silence. And it can be you.
I also want to add that the language you've used with him would be exacerbating the situation. And what is wrong with him wanting to leave the game if the game isn't working for him? Do you really have nothing else to do but play on the computer?
Sounds to me like you pushed him into continuing when he wasn't enjoying it and then got pissed because you pushed him too far and he got really mad. Yes, perhaps he could have used better behaviour in the game, but it would have been far more productive to say "I think you're right about stepping afk - let's do something else" But no, you chose to push him to continue the game and then blame him and label his behaviour when it all went downhill.
Then asking him if he was going to bed or needed more time to sulk just made it worse. Why not just say "hey, would you like to come to bed now?"
I think you're equally to blame. Yes, he may have been in a bad mood on the game, but you wanting him to continue playing despite him wanting to walk away...and then being verbally rude to him was out of line.
Start by apologising for your own behaviour and see how things go.
Never regret anything that has happened in your life. It cannot be changed, forgotten or undone. So, take it as a lesson learned and move on.