When you've done something you believe is wrong, how do you move beyond it?

First thing is you have to forgive yourself, since God already has.

Second, if you wronged a person (and they're aware of it), then you may or may not be able to make amends directly. Pending what happened, they may not be in a place to forgive you just yet, but as I said, it is *YOUR* forgiveness of you that matters.
If they don't know, and aren't continuing to suffer because of what you did, they you may be better off just keeping your distance from the person going forward. (Again, it depends on what happened).

And if there are memories that you just can't let go of, this will help:
http://www.examiner.com/x-26138-Spirituality-Examiner~y2010m1d17-Talk-6--How-to-get-rid-of-the-pain-of-the-past-Or-how-to-create-the-future

Ask me anything