Hi athenaaa,
I'm sorry to hear that your studies have not led to the type of improvement that you are looking for. From what you describe, I think that part of the issue might be in how you 'structured' your studies. For example, it's important to take FULL-LENGTH CATs/mocks at regular intervals (since there are Test-taking skills that take time to develop, but that can really only be learned by taking CATs over time) - so going forward, that will have to be part of your plan. Thankfully, the GMAT is a consistent, predictable Exam, so you CAN train to score at a higher level.
At this point, you might want to think of your upcoming Official GMAT as a "learning experience." While you might not score at a particularly high level, you should take careful note of all of the details of Test Day; you will then be able to incorporate those details into your studies (and how you take your future CATs/mocks) - and better train for your next attempt.
Before I can offer you any additional advice for your studies, it would help if you could provide a bit more information on how you've been studying and your goals:
Studies:
1) What type of study routine were you following? How many hours did you typically study each week?
2) What other study materials have you used besides the course that you mentioned?
Goals:
3) What is your overall goal score?
4) When are you planning to apply to Business School?
GMAT assassins aren't born, they're made,
Rich