"Wouldn't it be nice if there were a delete button for memories?"
I'm afraid there is no delete button, but there is something you can try....it worked for me...
Imagine putting those memories in a box...
You know the very high shelf in your closet? The one you put things on you don't need often, or at all? Those things and boxes are just there, not opened, or rarely.
Put that box of bad memories on the upper most shelf...Really, really visualize the details of doing it....It helps, truly, to move on.