Well, SubTonic, I have indeed found you to be quite the jerk in my time on the forums, but I've also grown to respect you for dealing with what you've got. I can also sympathize greatly with having terrible anxiety about these types of things, as I'm the same way. I'd recommend deep breaths, comforting music, and just psyching yourself up. Then just go for it, don't put it off.
It's a tough thing to deal with, but you're not alone. I have faith in you. And if they don't want to give you a job, just be a jerk to them. That'll show 'em.

Edit: Dammit, my advice came too late. Oh well. I'm glad it went well!