1. hair shirt - Noun
2. hair shirt - Adjective
an uncomfortable shirt made of coarse animal hair; worn next to the skin as a penance
self-sacrificing or austere
Source: WordNethair-shirt
I love my work with a frenetic and perverse love, as an ascetic loves the hair shirt which scratches his belly. Gustave Flaubert
I felt that I ostracized myself by my behavior, by the past, by living with all the regrets of my mistakes, that I sort of wore a hair shirt and beat myself up most of the day thinking and regretting why did I make such a mistake? Why have I made so many mistakes? Sarah Ferguson