Years ago, I consulted a priest about a difficult time in my life. He listened and then gave me the most consoling words I’ve heard. He said: Pray to God who sees everything as a whole, from the beginning to the end, and ask Him to look upon the thing that gives you sadness and ask Him to make something better out of that dark time. Do this every time this memory recurs in your mind.
We all have these times that caused us grief, regret, pain and the Evil one throws these memories at us years later, in his plan to turn us away from God.
So my recourse, among others (like praying the Memorare) is to pray to God to take that one painful moment and make something good come out of it. This is what healing is about. Think of this as your dose of God’s mercy.