remorse

This term describes a poignant, internal anguish that arises from the realization of one's own moral failure. It differs from simple regret, which can be felt for a neutral misfortune, by requiring a sense of personal culpability and a desire for atonement. As an uncountable noun, it does not take a plural form and cannot be counted with numbers. To quantify the feeling, speakers must use partitive constructions such as a wave of remorse, a pang of remorse, or a sense of remorse.