Hi Farzad,
I'm sorry to hear that Test Day did not go as well as hoped. Your 2 Official Scores are so similar that you likely continue to 'respond' to the GMAT in the same ways as you did during your first Official GMAT. A Score Goal of 550 is reasonable, but you will have to make some significant changes to how you handle the Overall Exam. Thankfully, you have plenty of time before September, so if you can focus on learning and practicing the proper Tactics, then I think that your Score Goal is achievable.
Before I can offer you the specific advice that you’re looking for, it would help if you could provide a bit more information on how you've been studying and your goals:
Studies:
1) How long did you study before each attempt at the GMAT?
2) What study materials have you used so far? What 'brands' of CATs have you used so far? Have you taken any CATs more than once?
3) What were the Quant and Verbal Scaled Scores on each of your Official GMATs?
Goals:
4) When are you planning to apply to Business School?
5) What Schools are you planning to apply to?
GMAT assassins aren't born, they're made,
Rich