A person who never regrets his wrongdoings is likely to repeat them. But excessive guilt is harmful. An important factor concerning regret is whether a person feels bad that he feels bad, or feels good about his regret….
Ask yourself, “Will my blaming myself help me improve or not?” To the degree self-blame motivates you to change for the better, it is positive. Self-blame that prevents improvement is counterproductive and should be overcome. When you stop feeling self-pity over your mistakes, your mind will be free to work on improvement. ~ R’ Zelig Pliskin