I don't see why he can't have friends and be concerned about someone else as long as he is being honest and truthful about the relationship. This may mean that both of you need to find a hobby you can share and enjoy with one another so you don't feel as threatened? You don't have to play an online game, but there are board games/card games/movie nights/etc that you can do to help cultivate the relationship. My parents have been together for about as long as you have, and they periodically do things like movie nights or cook for one another to help their relationship.

If my SO told me to stop being friends with my guy friends I'd be offended. It's like me asking him to not be friends with his female coworkers.