[Lawtan]

I tend to utilize something - like music or a game - as a quick way to try to calm down before I enter a known scenario. That achieves a degree of relaxation before entering something like that.

For unknown scenarios, I tend to be okay - in that my fear keeps me attentive and observant, but leads me to crash as soon as the situation is over.

I am not sure of the "reassure yourself you are safe"...but then again, I am paranoid and am never safe in my mind. I more remind myself that if I am in danger, it is best to face it as head on as possible. (Which, for me, means not running away). On the other hand, if the anxiety is more internal, it may help to remind oneself that they are human - a creature with a right to live and though quite fallible, not a monster.

Finally, if the scenario is around folk you know/who care about you, communication may be an excellent way to both acknowledge there is a problem, and gain some support.