How's Aikido these days? Had I been around in time, I would have recommended all the above but also some time to meditate and calm the mind. When I first started aikido, I would get all nervous and worked up and so I would sit quietly for about 10 minutes before the actual test and calm everything down. Sensei picked up on my doing this and the next test or two he made that a part of the pre-test preparation.
Just sit quietly and let all the noises and outside distractions wash over and away from you. And... yeah, don't forget to breath.