Memories relate to the past;& that past has passed.Tell yourself "I am glad it is behind me--everybody commits mistakes or has been wronged by someone.Am i someone special that it should not happen to me?I shall take care that it does not happen in future.And what are 1,2,or even 4,5 memories in a lifespan of-- your age x 365 days ?"
Just concentrate on the present.Stop focusing on the dismal aspects of your life.Take heart,life is not all bad.
You can get more help from "Beat the blues" http://jeeteraho.blogspot.com