You "could" be bi-polor. You don't need to have extreme highs in order to be bi-polar, there are many different types, and quite honestly, and in my completely non-professional opinion, it sounds as if you "may" qualify. SSRI's tend to bring out bi-polar tendencies also.
Oh, and I don't feel sorry for you, but I DEFINATELY feel for you. Read some of my recent journal entries and you will know why.