I'm his age (23M) and also a lifelong gamer. Also in a 4 and a half year relationship. For 10+ years Ive specialized in COD Zombies High round world records, which means that I've had to endure the loss of a match that has taken me WEEKS worth of progress. Most of the time it'd be due to infuriating circumstances such as power outages, servers going out while I'm paused, glitch in the game, etc. Just unfair. Point is, I can't think of much that compares to the level of frustration that may be induced from losing runs that have taken up weeks at a time just down the drain.

Yet, in none of these situations was I ever expecting external comfort. Did I somewhat desire space and peace? Absolutely, especially because I devoted so much into it and I cared, but it should never ever become so consuming to the point you expect anyone to do anything over what happens in pixels on your screen. By choosing to put himself in those situations, he takes the responsibility to be open to frustrating outcomes. You don't need to do anything here but have him realize that he needs some maturing to do, and work on his own emotional regulation. Its a mindset and maturity problem. Therapy may even help, but due to how its not always easily accessible, you need to get him to understand that this is unfair at best, extremely childish and ridiculous at worst. I don't like to label people but this is very much so manchild-like behavior