Don't change your study habits for the last few days. If you normally study for 2-3 hours a day, then continue that up until the day before the exam. If you all of a sudden start studying 5-6 hours a day, your body will not know how to react, your mind will feel as if it can't learn fast enough, and you'll be stressed.
Go to sleep early the night before the test. Chances are you won't fall asleep right away. Although i didn't do this, you might consider taking a half a dose of Benadryl or Nyquil to help you sleep. However don't take a full dose as you might feel drowsy in the morning.
Don't do any studying the day of the test. The night before, write down a timeline and a plan of what you're going to do on test day. then, wake up as early as you can and stick by the schedule. This will help you remain calm before your test, and it will prevent you from feeling like you have to rush to get everything done.
Another thing that helped me was going to the gym a few hours before my test. If you can't make it to a gym, maybe try going out for a run, or doing some pushups or situps in your house. Just remember not to overdo it - you don't want to have a pulled muscle during your test!
And most importantly - just know there is no 100% way to eliminate anxiety. It's perfectly normal to be nervous before the test; you just have to control it as best you can, and not let it take over you.
my GMAT debrief:
https://www.beatthegmat.com/came-through ... 44327.html
You will not fear the terror of night, nor the arrow that flies by day,
nor the pestilence that stalks in the darkness, nor the plague that destroys at midday.
A thousand may fall at your side, ten thousand at your right, but it will not come near you.
- Psalm 91: 5-7