The phrase "on a crying jag" can be replaced with a variety of synonyms to express intense emotional distress or bouts of crying. Some common alternatives include "in tears," "emotional outburst," "weeping marathon," "meltdown," "crying fit," "sobbing spell," "bawling session," and "tearful episode." These phrases can be used to describe moments of intense sadness, grief, frustration, or overwhelming emotions. Whether used in a personal context or to describe a character in literature or film, these synonyms effectively convey the intensity and duration of a crying jag.