He sounds like a good guy. He just struggles with addiction, something that depression makes even easier to fall into. I know you said he is going to therapy, and that's great, but I wonder if he would be receptive to you going along? Or perhaps you could set up a different therapist for the both of you?

He may not be approaching the subject of his gaming addiction and how it's effecting his relationship. And I think a therapist would know best how to work with you individually and as a couple on how to handle it. It takes a lot of recognize the problem, but it takes even more to change the behavior and he may not know how.

Wishing the both of you the best, OP!