Prior military

My husband joined at 18 and was out at 20-21 due to injury's now he's 28 and he doesn't like to talk about being overseas with me he will but only rare occasions and only if he just needs to vent. We recently saw american shooter, that's the first time I've seen him cry and have a hard time like that. He stayed up talking about his old military buddy's who didn't make it home and how he wishes he could take their places. (We didn't know each other then we've been together 2 years) but I know that when he first got home it was bad he woke up shooting walls.. I was wondering if anyone has had anything like this years later its all coming back just not so sure what to do for him he knows I'm always there for him but idk