Communication is the key, keep trying genlty and opening up to him about how you feel.
It could be that he's sruggling internally with issues of arousal and potency and, like all men, bottling it up. It could even be as 'simple' as a loss of confidence in sexual situations.
Try the talking method and strengthening the relationship.
Lovehoney has lots of fun toys and outfits that can satisfy both of you too, maybe a tiny bit of sexual exploration will help to rekindle that passion too.
I know it sounds cliche, but talking is the best way to move forward - it can be difficult and sometimes painful, but you'll come out stonger as a couple.
It looks like you both need to have that "chat" with each other and get things on a better footing. Communication is key to a relationship as the others have already pointed out.
Why not try and embrace his hobby perhaps get a sexy military uniform .It could be a way of doing more things together which I think is what is perhaps needed first. If he is a wargamer then let him teach you the basics and then game together . Loser can always do a sexy forfeit.
But whatever you decide to do you both need to talk to each other for anything to work.