Years of guilt feelings over a specific matter can sometimes be overcome in a surprisingly short time if a person adopts a different perspective in viewing the matter. Frequently, people blame themselves unnecessarily. If you have irrational guilt feelings, give yourself a speech why you need not blame yourself. Take a piece of paper and write a list of ways to judge yourself favorably. Be careful not to do this with matters you should really try to correct. We are referring only to irrational guilt feelings, not to situations where a person wants to rationalize his failure to make difficult, but necessary, changes.
If you find it difficult to judge yourself favorably, ask yourself, "How could I judge someone else favorably in this matter." Guilt-ridden people often find it easier to excuse others than to excuse themselves and this can be utilized as a tool for lessening their own blaming thoughts.
(Rabbi Pliskin's Gateway to Happiness, p.231)