Pysch, worried about you man, you've posted many depressed/stressed threads this year.
1. It's just a test, nothing more, nothing less. Prepare, do your best, then screw it. You'll be alright.
2. As stated, beware of other students. I usually reclusive around test time or hang out with guys I know won't be talking about the material. Med school is designed to freak you out about the little details and make you feel like you have to know everything, YOU DON'T HAVE TOO. Don't be afraid to admit you don't know everything, concede some details. Beat the system!
3. It's just med school, nothing more, nothing less. Many people take med school so seriously and it can get you down. Relax, have some fun, enjoy the moment. What happens, happens. Half of it is luck, if she smiles on you and your tested over what you studied, rejoice. If she craps on you and you are tested over the many tiny details you didn't study...get pissed at her it's HER fault.
4. Life is short, so is med school.
5. Find friends who have mastered 1-4.
Good luck, it's rough, they don't want it to be easy.