I can't really answer your question, Zinco. But I do know that there have been times, mostly when I was working, that I was involved with something where I simply could not allow myself to feel depressed. So, for that period of time, I would suppress any depressive feelings that I had. But then, once whatever it was I was involved with had ended, I would be hit with a tidal wave of depression. It was as though the depression I would typically have been experiencing day-to-day built up in my system & was finally released all at once.

Perhaps what you've experienced is something similar. You were determined not to fall victim to depression while you were on your trip. But, once you were back home, there was no longer a need to fight it off & so it rose up & hit you all at once. But, now that this "wave" has passed, you're feeling better. Hey... sounds like a good theory anyway... doesn't it?