Hey Varun,
I have a couple of suggestions for you
Try and limit yourself to revisiting your error-log if any(else go through the mistakes you
have made in the OG and the GMATPrep tests). Make flashcards(hand-written about some
of the rules that you having a hard time remembering and read them again and again over
the next few days. This is a post which talks about what to do and what not to do 3 days
before the test
https://gmatclub.com/forum/what-to-do-3 ... 71542.htmlIn order to minimize the nervousness in the beginning - you can do a few questions an hour
before the exam to get into the zone. This must help mitigate some of that nervous energy.
It is very important to have faith in your abilities. Remember you have toiled really hard to
get where you are and you deserve this

All the best for your exam and do let us know how it goes for you.
Hope that helps you!