Hi Glenn
I don't know the way Pete meant, but to focus your mind, listening to side A, on any constructive goal could help.
You might also try stating a goal to be feeling great value in yourself, your life and your future unconditional of past relationships.
Also, try and check to see if there is anything you could learn, if you learn something your future relationships can only get better.
You can also try a couple of rounds of forgiveness affirmations like, "I forgive all", and "I am forgiven".
Allow space for your feelings, allowing your feelings to be and to observe them, from a distance, will speed their release.
Hope this helps.
Grant
