Just from an outside perspective i think your husband sounds more depressed than anything else. I used to be that person granted i was not in a relationship/having kids. It was during teenager/early adult years in which i would play 16h every day and literally skip everything else just to avoid all the terrible things that went wrong and were going on in my personal life. I was just in an awful place mentally.

When you spend so much time doing something you will eventually get really good which only fueled the problems, in my case at least. World top rankings in raiding and multiple arena rang 1's just made it worse because it was the only thing that made me feel good about myself, which got really addicting.

Honestly the only turning point for me was meeting a great guy (met him ingame) and getting really sick shortly after. Those 2 things happening were the only reasons i realized i wanted more from life than what i was doing all those years and thats its not enough for me anymore. After i got to that realization it was actually pretty easy to change. Been having multiple breaks from WoW since .. i still play a lot when i play but not at all addicted anymore.

All of that being said i dont think theres much you can say to reach him, making him feel guilty will probably only make the problems worse. If his depression is something work related a switch there might be the only solution.

Best of luck