Hi Pranav,
GMAC has publicly stated that a Test Taker's score is within +-30 points of actual ability. Assuming a similar 'swing' in your CATs, your Official Score is 'in range' of those practice scores (and I don't see any 'red flags' in how you took your practice CATs), so it looks like you were practicing in a realistic fashion.
As far as the AWA is concerned, most Schools expect applicants to have a minimum of a 4.0 on the AWA - but most Schools do not put too much emphasis on it. With a 4.5, you have that part of the application 'handled.'
You mentioned something interesting about Test Day - that you arrived 1 HOUR before your Exam. That's not too common, so I have a few questions about Test Day:
1) How did you sleep the night before your GMAT?
2) How long was the ride to the Test Center from your home?
3) Were there any distractions at the facility or during the Test?
4) What did you do during the two 8-minute breaks?
5) Did you finish any sections early?
6) Did you have to rush to finish any sections (and guess on questions just to finish on time)?
GMAT assassins aren't born, they're made,
Rich