Its Internal

Maybe its just me, but have you ever been having a decent day, not the best or the worst, but everything is basically okay and you get in a really bad mood? Happens to me all the time. And today, as I was with some friends this happened.  I got randomly quiet and killed my own mood. The problem is what I think about. It has nothing to do whatsoever with the people I am with nor does it have to do with my surroundings, but I become depressed almost instantly. I don't know what to do either at moments like these. To those around me I am "pouting" but to me I am dealing with an internal conflict. I feel sorry for the people who have to be around a Debbie Downer, lets just say, but I can't exactly control my subconscious. Apologies to all who feel that they've wasted their time by reading this, but as I'm sure you could've guessed, I am in said mood.