I work in Africa, 2 months on, 1 month off, and one morning I woke to find that I'd been burged during the night. I stay in a villa, on my own, and on the kitchen table I found a huge knife that the burglars had left behind.
Luckily I had locked the bedroom door or I dread to think what might have happned, and luckily I never heard a thing.
I didn't go out of the house for something like 6 months, then I was speaking to one of my ex pat friends and he asked why I hadn't been out, he knew about the burglary. It was this guy who told me to speak to someone because It sounded like depression was setting in.
I was fine when I was home with my wife and kids but the thought of going back to Africa and the villa was horrible.
My point is, sometimes you just don't realise that depression is taking a grip and admitting it to yourself is difficult.
There are reasons for it, and it's nothing to be ashamed of.
Are you okay now mate, as that sounds like text book Post Traumatic Stress to me ?
Constantly thinking about " what if ", nightmares, constant anxiety, not wanting to be in crowds or strange places, etc ?