ramshorn:
definately go for the interview coach asap, but a quick word of advice (for what it's worth)
go there to get a better understanding of yourself, ie. your key strengths and potential weaknesses... I didn't goto coaching, but took this approach and found it helped out in my interview.
Also, don't try and anticipate the questions in the interview, as it may be completely different to what you expect (at least it was completely different to what I expected!)
Good Luck!
