I was in the same boat. Don't let anxiety overwhelm you during the test. During the test I notice my nerves were getting to me. So I took the time to close my eyes, took a couple of deep breaths, and told myself to calm the heck down.
Fitz, hollier book, and the 2000 ANP & FNP practice questions was what I used to review. Honestly, using your "common sense" will help you with the test.
I did not postpone my test. I studied like crazy like you. I couldn't take the anxiety anymore, so I changed the test 3 days early. I reviewed my weakest areas the day before the test.
You studied enough! All you can do is try your best.
Good luck. You can do it!!!