Hi dina98,
Most Test Takers spend 3 months (or more) of consistent study time to hit their "peak" scores. Studying for the GMAT is not like studying for a College Test - very few Test Takers can "cram" for it and score at a high level. As such, you have to look at this process as more of a part-time job - you'll spend 10-15 hours per week (or more) on it throughout the 3+ months of study. This is all meant to say that you just might not have studied enough yet to hit your goals.
Using the data from your Official GMAT, you clearly have a greater opportunity to pick up points in the Verbal section, but you also have some points available to you in the Quant section. With a Q45, you're likely really strong on the "math" questions that you come across, but you're missing out on the strategy "points" and you're missing a bunch of DS questions along the way.
Before you invest in any new GMAT products, you should take advantage of all the free resources (practice problems, Trial Accounts, etc.) that GMAT Companies offer so that you can "test out" a Course before you buy it. In that way, you can purchase a product that best matches your personality, timeline and budget.
GMAT assassins aren't born, they're made,
Rich