But you can't change what is over with. All the memories can do is change you right now. Let it go. One way I found that worked wonders for me and I share now to help you, is to take it up in active prayer. What I mean by that is this.
Ritualize the prayer of release. Give it up to God. Find a time when it just feels right to let go of things that bother you. Find someplace where you can relax and be alone with your thoughts. With a paper and pencil write down everything that comes to mind that you regret. All those things that burden you now that are long over.
And when you're done burn the paper. See all that weight being cast away in fire and cleansing your life of it so that it is not in the past where it belongs. And your future is in God's hands.
There are a great many Bible verses referring to
God's power and the power of Fire. Release your burdens of things that are long over with. Realize that all that you've done is not who you are. They are things you did that helped you to learn how to be you, learning from those things, right this moment. (HUG) Find peace child of God.