Life is never the same after you have been deployed to a hostile situation while serving in the Military. I for one know this, I am a Veteran of Desert Storm / Desert Shield.
I am not afraid to admit that I have had my moments in my career, where I was depressed at work. Not accepting it, and not finding ways to deal with it, just causes you to fall deeper into the problem. I was fortunate that my last employer had programs set up where I could talk to someone, and help me get back to the path that I was use to walking on.