I don't personally know you, so it's difficult to say for sure, but it sounds like you probably just aren't terribly comfortable talking in front of people you

I don't personally know you, so it's difficult to say for sure, but it sounds like you probably just aren't terribly comfortable talking in front of people you don't know well. The key is to basically stop caring what strangers think of you. You could try doing karaoke or amature night at like a standup club or poetry reading. Strike up conversations with complete strangers. Another thing to keep in mind, if your personality doesn't mesh well with the interviewer, there is a good chance that you wouldn't have fit in well with the corporate culture.