Hi RAS85,
Test Day is a rather specific 'event' - the details are specific and they matter, so you have to train as best as you can for all of them. The more realistic you can make your CATs, the more likely the score results are to be accurate. The more you deviate, the more "inflated" your practice scores can become - and that's what happened here. By taking the CATs at home, taking them at different times of day, and anything else that didn't 'match up' with the details of your Official Test Day, you weren't properly training for the FULL GMAT 'experience.'
Beyond those details, we also have to discuss just how 'early' you finished the Quant and Verbal sections. As a general rule, finishing a section significantly early is NOT a good thing. For example, if you finished a section 10 minutes early, then that's a significant issue - since finishing that quickly almost certainly means that you rushed through questions and made some mistakes. If you finished 10 minutes early, but you spent 5 minutes on each of the last two questions, then that 'issue' is compounded, since you would have completed almost all of the questions in 55 minutes (instead of 65 minutes). So how early did you end up finishing the Quant and Verbal sections?
Regardless of this recent outcome, the GMAT is still the same consistent, predictable Exam that it's always been, so you CAN train to score at a higher level. You'll just have to be a bit more rigorous about how you study and commit to doing all of the necessary work (on the pad) so that the little mistakes that hurt you this time don't occur again.
1) What is your goal score?
2) When are you planning to apply to Business School?
3) What Schools are you planning to apply to?
GMAT assassins aren't born, they're made,
Rich