When someone triggers the fear in you, remember our resonance quality. We wave, vibrate with the environment. It is a fear from the other which is making your strings tremble.
Very often, the person (who throws fear) is only a frightened child inside of himself, who choses an attack strategy for defense.
The most logical thing to do in this situation is to calm the trembling person.
“With me you have nothing to fear, I woun’t hurt you!” – should signal all your sence-transmitters.
Slowing down your vibrations, you can also calm him.
When you realize that this fear doesn’t belong to you, you can slow down your vibrations. Focusing on your breathing, slowing and deepening your breath.