The phrase "haddest fit" is an archaic way of saying "had a fit" or "had a tantrum". Some synonyms for this phrase include "flew off the handle", "lost your cool", "blew a fuse", "went berserk", "had an outburst", "threw a tantrum", "had a meltdown", and "lost your temper". These phrases all refer to an intense emotional reaction, often characterized by anger or frustration. It's important to note that while having strong emotions is a natural part of being human, it's important to learn healthy coping mechanisms and avoid hurting ourselves or those around us during these times of heightened emotion.