There was an interesting movie some years ago called Eternal Sunshine of the Spotless Mind that dealt with two characters who had broken up from a relationship. One of them went to a specialist who could erase memories. That movie chronicles their adventure.
While we don’t necessarily have this magic overtly, all of us DO have the ability to control which memories dominate our minds, and with enough focus, we can forget what we don’t want to think about by CHOOSING NOT TO ACTIVATE THOSE THOUGHTS. Granted, our minds are biochemical factories that are predisposed to re-creating the patterns of thought that are habitual. HOWEVER, this does not mean that we are helpless bystanders, condemned to watch re-runs of our least favorite times!
Despite what you believe about your mind, I assure you that you have at least as much control over it as you do over a television! Imagine that your mind is simply a screen just like your TV and that you have the remote to fast forward, rewind, or stop what you see! In truth you should be able to practice this level of mental discipline often. You have to be aware of when you are playing unpleasant thoughts, either of the past, present or future. Then you need to use wisdom to overcome those thoughts, either by stopping them or changing them into more useful images and feelings. Eventually, the unpracticed thoughts will fade from your memory! The rewards of this will be heightened levels of energy and positive feelings, since the emotional drain of negativity will no longer be sapping your mental/emotional energy!
Good luck! If you would like help on this please see my wellness coaching services!