I'm concerned about your post on a number of levels and was very worried about posting a response because I have to advocate for your son. As an adult who played online games, I know that the relationships developed "in-game" are real. Having your gaming computer sold out from under you is a very serious transgression to a gamer which could feel equivalent to having your heart ripped out! It's could be compared to a parent having an ability to rip away all friendships of their child in one fell swoop. If your son has been playing for 2 years, I would imagine he feels very strongly about those in game relationships and may also feel that the friends in the game are relying on him, worrying about why he suddenly disappeared out of their world, all kinds of things. And they are likely VERY worried as is he!
So with all the huge, huge turmoil the act of selling his computer would cause, it was then compounded with some even more serious words, telling him that he's a "jerk" etc. that would then have further shut him down. All the anger, all the things he could tell you about how he's feeling, I worry would then turn into a boiling nasty lump inside him that will rear it's ugly head over and over. He would feel disrepected and not understood and with no voice to express all of it.
For a parent to receive respect from their child they have to model that same respect toward their child. Listen, believe me, I understand that the dispassionate stance breaks. But even when it does, for me, certain words can't come into play. As a parent, our judgement of our children, the words we use, the actions we choose can last for them forever and somehow we have to find a way to not go to that place, to not use harmful words or actions. And most importantly, if we do go there we have to attempt to rectify it and very, very quickly.
I believe as parents we owe our children heartfelt apologies when things fall apart like that. And I appreciated your honesty with it and also your statement that you know it was wrong. So from that place, if you act fast, maybe you can undo some of the damage. For me that would involve an apology with the understanding that he probably won't accept it, but also a statement of wanting to know how he is really feeling and hearing it without comment. You could also ask him what can you do to make this better. If he says "buy me a new gaming computer", I personally would not only do that but would involve him in configuring it!
Bottom line, you don't want him shut down and depressed. You want him to feel like you can connect to what matters to him even if it is something that concerns you. From a place of respect changes can be slowly made, but from a place of disrespect much worse will follow. I hope he is ok and I hope you are ok. It sounds stressful. And my apologies for being so direct. Lord knows I don't have all the answers and went through some terrible times with my child...but when things finally turned around, it was the respect and connection, from the heart, that forged the unbreakable bond that kept us going.
"The world is full of story shapes."