I am glad to hear that you are learning a lot. Studying for the GMAT can be a gratifying experience actually, as well as a stressful one. However the GMAT is a test of how you think rather than what you know. I wonder if you are currently thinking in such a way that you could earn that 700 that you strive for...

You need to analyze the body of work that you have - lots of practice tests! - and see why you are missing questions. What can you do to stop making those mistakes. Here is are two articles that talk about the three kinds of mistakes and what you need to do for each: https://www.veritasprep.com/blog/2013/01 ... -the-gmat/
https://www.veritasprep.com/blog/2013/01 ... -the-gmat/

Then you need to purchase the GMATPrep Exam Pack 1 add-on. This will give you two additional GMATPrep tests. After reviewing your procedures and working on adjusting your thinking take the next GMAT Prep. If you are not at 680 or 690 as a minimum you will likely need to postpone your test. Remember to postpone before 7 days prior to the exam so that you will only be charged the $50 fee.

If you do need to postpone let me know and I will give you some thoughts on how to try to change the way that you are looking at these problems.