Like others have said - the practice you've done until now will pay off. Trust it. Keep busting hard, and practice tests are key for essays. Just keep doing them.
For me, both for essays and MBE, memorizing the law was key. I used flashcards but also tried varying memorization techniques to remember. The one that worked best for me was quizzing myself, outloud if necessary. Really helps remember.
But really, it all comes down to busting hard now, then really tapering that down the last day or two before. Relax, trust the process, you'll be good.
And boy do I know the anxiety, I was in your spot a year ago. Good luck man!