I don't know why people don't stress this enough but you need to do countless computerized practice tests. I personally used to take my practice tests in public libraries that I had never been to before just to emphasize test-day conditions.

In short, do more computerized practice tests and emphasize the following:
- Uncomfortable, unfamiliar test-location (public libraries worked for me)
- Take practice tests during the same time of day as your real test.
- Eat/drink what you're going to consume on test day (If you're going to drink coffee beforehand on your test-day, drink coffee before your practice test)
-No Phone, no distractions.

Hey, I understand where you're coming from.

Been blogging about my personal experience having taken it 2 times already and working on my 3rd attempt for end of Nov.

A few lessons I learned:
- Quality not quantity. Focus on really understanding and identifying specific areas of weakness - eg what subject areas in math are you weak at? In Verbal?
- Keep a positive attitude - this test does not define you! And... you ARE going to get it the 3rd time! Why? Because you're capable of it and honestly... it's not a hard test - we just make it harder by letting lack of confidence get in the way!
- Dont' take practice tests all the time - do questions and build up.

Good luck!