There are plenty of substances to mask anxiety, but anxiety is good in reasonable quantities. Unfortunately, the best way to make troubling anxiety manageable is to utilize cognitive behavioral therapy tricks...basically slowing yourself down, breathing, removing oneself from upsetting environments momentarily (treating the sensorimotor responses first), then purposefully replacing distressing thoughts with positive thoughts...rinse and repeat until it becomes habit and episodes of high anxiety become less frequent.
Tough but a worthy skill to learn, I think.