I can relate to so much on this page.
I'm still finishing my undergraduate senior year, though. Whenever I'm about to graduate from a school, I get really (irrationally) worried something is going to go wrong and prevent my graduation. Unfortunately, the stress almost works as a form of self-sabotage. I remember, when I was transferring from community college to my university, I suddenly froze and became horrifically terrified that I might somehow fail my chemistry final and not be able to graduate. (I had a B+ / A- in the class!) My chemistry professor practically had to talk me into sitting down and taking the final. I was actually that panicked. (I did great, though.)
It is too weird because I normally function insanely well under stressful conditions. I only seem to recognize the insanity when I'm about to graduate, and then I suddenly see all that I'm doing and ask myself, "Hey, wait a second, how am I doing all this...?!" And my confidence goes poof!
But now that I've been accepted to graduate school, it's even scarier. :/