The appearance of things to the mind is the standard of every action to man.

You never act on the world directly; you act on how the world looks to you at that moment. Usually that is harmless, because most appearances are near enough to accurate. It stops being harmless when the appearance is loaded, when a raised voice looks like danger or an unanswered message looks like rejection, and you respond before noticing you interpreted anything.

When a reaction seems too big for what happened, treat that as a sign that you are responding to the appearance rather than the fact. Say out loud what actually occurred, stripped of what it seemed to mean, and see whether the reaction still fits.