I remember starting a thread years ago about a therapeutic exercise that involves re creating new memories out of old ones and giving them a happy ending, to create the positive emotion that would replace the negative one that comes from the real event.
Everyone scoffed at me...but it actually does work to help build more positive emotions that can and do replace bad feelings. It doesn't mean you are lying to yourself, it means you are actively using your imagination to create a better way of feeling and imprinting that onto your old memory and neural pathways. I see nothing wrong with it...AND, it works really well to sit down and write a new memory...the way you would have liked it to turn out. You know what really happened, and have felt like crap about it, so it's not like you are in denial about it...but you can create a better scenario using your imagination that replaces the bad feeling with a good one.
If it makes you feel good then it can't be that bad, right. I don't expect everyone to believe me or agree but everyone I know who has given it a go has gotten something positive out of the exercise.