What is your target score?
With only about one week left, there is not much you can do to drastically improve your score. Part of your problem is that you are studying GMAT 8-12 hours a day for almost every day. This is not the best approach to learn the GMAT. I highly doubt that you were productive during all those time. You have to find a balance between studying and resting. GMAT is not a memorization test, instead it is a thinking test. If you are tired before the test, the battle is already lost before it begin. So, if your mock test scores are 50+ points from your target score, then I would suggest you postpone the test and then change the way you prepare the test.