Congratulations on getting through college. That must not have been easy and you managed to complete it despite your social anxiety. I think that's a fantastic effort and you should be totally proud of it.
It's difficult to properly prepare for an interview, but you have to take a risk with them and if you muck up the first time, try again. The only way you'll get better is to keep doing it.

Exposure therapy - a pain in the bum but it is effective!
Welcome to the forum.
