so moody!!!

idk what is wrong with me, I've been moody these past two days. I try and try to be happy but I just can't. I even had sex with an orgasm and still didn't change my mood (which it always does) Maybe it's the fact that my fiance is going out of state, leaving me for a whole week for work? Maybe its that attachment that I have with him that's triggering my mood swings? I just got off my period last week so it can't be related to pre period emotions. I wish I knew what's going on with me. has this ever happened to anyone???