Well, it been super common among soldiers forever. If it’s debilitating you need to lean heavy on the guys you served with and your friends. I’d medicate only as a last resort, and then anti-depresants ONLY, NOT alcohol or other drugs.
If it’s not affecting your life in a significant way (wife kids, family, etc.), and you’re just doing stupid shit like making circles around the bar you are going to, checking out the alley and the back door, keeping your back to the wall, being a general paranoid dick, .etc., just be mindful and it will slowly go away. if it's actually messing up your life go to your buddies, and do what they say even if you don't like their advice.
Mine was just the stupid shit and being an asshole. I only got real anxiety attacks around crowds. So I avoided them for a long time and slowly went to more and more crowded places till about ten years later I could be in a big crowd without feeling terribly uncomfortable.
I was pretty much in total denial about it and argued with people about how relaxed and mellow I was, which was utter horseshit looking back on it... Still it just took time, but I will say that I did not just come home and go from intense situations to full stop. I picked occupations that still had a lot of intensity and allowed me to be a leader, and that helped me a lot.
It effects everyone differently. I had to slap the shit out of a retard, Army grunt, friend of mine who came back from the sandbox with his jaw blown off and reconstructed (very well I might add). He was acting like a total, pussy, welfare bitch on his disability and PTSD checks. There are guys with no arms and legs who don't let that happen to them! Those checks almost fucked up his life permanently. I had to be on his ass constantly being a total dick and insulting him all the time to make him get off his lazy ass and do something with his life besides feeling sorry for himself and self medicating. It got to the point where almost every interaction was a very negative one. He thought I was the biggest asshole in the State and said as much often.
Today we are back to being good friends, and he has told me how grateful he is that I was his one friend who didn't feel sorry for him and demanded he get up off his ass and do something instead of joining the pity party with everyone else. I certainly don't take credit for anything, because he had to do it himself or he would still be a waste of space, but today he owns a Plumbing and GC business with about twenty-five employees and a million bucks in machines in his yard. He is rocking, happy, and his PTSD is not worth mentioning if he even still has a touch.
I don't say this is some primmer for everyone. Everyone is different, and there are people with real shell-shock who need professional help. I do think they're the minority though. Most people need to be treated like adults and you must expect them to behave like adults or you're doing them no favors. I'd say the most important thing if they have serious PTSD is not to drink and party with them. If It's really bad demand they get real help, and be a REAL friend; the kind who tells it like it is, and expects very good things from the few people who get to be called "friend". THEY have to do it. You can't do it for them. You can only encourage them to get help and to help themselves. If all they say is, "Woe is me", they're not going to do it, so the first thing is to snap them out of that shit. Sometimes you got to be a dick. Just my experience.