Relaxation and Concentration Tips for High-Stress Situations?

Two weeks from now I'll be taking a test (related to my job) and it's a requirement to pass it. I need to be able to concentrate for several hours and I know from the past that stressful situations make my tinnitus BAD.

I'm going to ask the persons in charge of overseeing the test if I could use my mp3 player and headphones to play some tunes/masking track, maybe that would help. I thought about taking a Xanax or smth but I fear it might impair my cognition (I need to excel!)

How have you overcome situations like this?

 

just read this , how did the test work out?

how did the test work out for you?