In this reply, I won't comment on reliving upleasant memories over and over in spite of the fact you don't want to. However, I will offer a suggestion on how you can "forget" memories.
Reliving memories is similar to telling them to others. It reinforces them.
A simple suggestion, then, is to think or do something else you enjoy when you find yourself reliving a traumatic/negative/painful experience. This stops the reinforcing cycle, and can help avoid the anxiety associated with the unpleasant experience.
Also, if you have been using Memory Supercharger, you may want to read the following thread: http://www.learningstrategies.com/forum/ubb/Forum4/HTML/000284.html
In particular, see Paul's reply on repression and the use of his paralimal tape Memory Supercharger. His is the the eight message in the thread.
