There are a bunch of study guides out there. Utilize them! Reread your notes, take the free online tests, study with your classmates, then do it all over again. I made it my 40-hour-a-week-job. I bought 2 hard copy NREMT-P books, i studied my notes, i conferred with classmates, i took the free online tests, i talked with co-workers, and i took the test. I walked out after 71 questions, and found out a few hours later I had passed. In my experience, the test is designed to make you second-guess yourself. But if you stick to your guns, fall back on your education, take your time, utilize your resources (they give you blank paper for your drug calcs!), you should be fine. I realize test anxiety is a real thing, but c'mon, it can't be any more stressful than your internship! If you can pass didactic, pass clinicals, and pass your internship, NR really shouldn't be that big of an obstacle. If this is what you really want to do for a living, a standard aptitude test shouldn't get in your way. If you fail, just remember this: YOU GET 6 CHANCES TO PASS!
When you do pass, and you will, let us all know so we can celebrate and welcome you. Good luck. Hit the books. Pass that SH*T!