Combat veterans and others who suffer from extreme guilt must forgive themselves as a first step to healing.

In the essay, Thinking and Feeling About Forgiveness, by Howard Lipke, phD, 10/1/09, the following quote is extremely helpful in understanding how overwelming guilt and resistance to self forgiveness can backfire.  The complete word document can be found at, http://www.howardlipke.com/  
“In discussing self forgiveness it is important to consider that the self punishment of always feeling guilty, which I define as anger at yourself, usually backfires. People can take only so much of this and then start to get angry and turn the blame back on others. A difficult alternative to constant self blame would be leading your life differently, being more careful, building positive habits. This is usually more difficult for people than feeling bad[1].  Which is why people so often punish themselves by feeling bad and screwing up their lives, than by making changes of habits and forgiving. The feeling bad seems to never go away, partly because depriving yourself of pleasure, or hurting yourself, does not usually make things even.  It actually makes the-thing-you-did-that-you-think-you-have-to-punish-yourself-for worse, by depriving everyone of your potential to learn from what happened, reconnect, and do good.”