Letting go of past hurts and pain is the hardest part, I think. I know that for me, I held every bad bit in my mind and went thru it all like reciting a litany, getting angrier each time. It took me years to forgive the hurt and pain, and the anger I held damaged my health.
There is no way I can forget incidents, but I don't keep them in front of me anymore, just filed them away far enough not to keep popping up.
Keep working on you, and eventually the past will stay in the past....unless something is repeated and then you can use those painful memories to motivate you into action that is to your benefit.