Feeling badly about making a mistake is natural, but punishing yourself forever is never appropriate.
I urge you to fully examine your beliefs about mistakes and forgiveness. Most people cannot answer this simple question: “How much penance is appropriate to expunge your mistake?” I have seen countless people who are continually punishing themselves in an infinite variety of ways because of a perceived transgression in the past. Holding yourself to a so-called higher standard (others could be forgiven for this, but not me) does not make you a better person. It only makes you a more miserable person….
It is a choice if you focus on the worst parts of you, rather than the good. If you are having difficulty, then focus on helping someone in need, rather than wasting your time and effort on chastising yourself. Do something positive. Choose to ask for help — from God, your spiritual advisor, or your friends. Be honest and admit that you are in charge of how you treat yourself, and start treating yourself the way you would a friend.
— Christel Nani, Sacred Choices, p. 230-232