I usually get it when things start to go out of hands (unexpected errors or input, distractions from many external factors etc).

Things that help in my case include: deep breath (mini-meditation), going out for a walk , playing an instrument (not actively practicing, but rather laying my hands on the piano keys and let the subconscious take the wheel).

Things that definitely do not help: eating (in these moments I have zero self control and would pick unhealthy food which would make things worse) and attention-seeking distractions (social network feeds, mindlessly scrolling infinite lists of questionable content).