Did you actually apply for this job or was it just offered to you? If you actually took the time to apply for it and
then turned it down when offered... I'm not sure what to say about that.
Seriously, dude. Unless you're completely full of sh*t, you've got to seek some help. Isn't there a university counseling center or something you could go to? Your depression has started to really negatively impact your life if you're turning down jobs that you wanted because of it.
Turn off your computer and get some help.
"How do you like THAT 'misanthropic panache,' Mr. Goldstone?" - PalJoey