penance – voluntary self-punishment to atone for a sin, crime, etc
It was a subplot in the series ‘Elementary‘, and it seems Sherlock had a drug addiction because he wanted to numb himself from all other feelings, due to something that happened back in London. Sherlock said ‘You always know it, Watson. If you didn’t, it wouldn’t be penance.’
And I can totally relate to that.
I looked back at my life and during the major down points, I always blame myself for the state of things. I may not acknowledge what I did thereafter was penance, but deep down, subconsciously, I always know.