hey good luck with the doc! you're probably there as i write this, but, oh well. it sounds to me like you definatly have some form of depression, but what do i know. i hope you find solace in knowing that depression is pretty treatable. and if you find out that nothings wrong with you, then i would say you probably need some kind of change in your life.
and i know this sounds cheezy, but if found that excercise is a kind of natural antidepressent, i aways feel good afterwards. but yeah so tell me how it went