I have a job interview tomorrow for a real office job that would pay 50% more than I make now at 2 jobs, so I am really excited.  Except I'm afraid of myself.  I haven't told anyone I have the interview cause I'm so scared I will mess it up.  Talking to people is so hard for me.  There's always a point where I feel I've done or said something wrong and it goes downhill from there. I doubt everything I say, everything I am, I stutter, I might lie, I might go into a weird kamikaze autopilot and end the whole thing with apologizing for wasting their time.  

Does anyone have any advice, maybe has been through this and found a way around it?  Or even just support.  I just don't want to mess this up.  I know I could do this job and that my family needs it.