“Are interested in one particular aspect or the whole verse in general?”
Although we are forgiven for our sins, it is not as though they never happened. How is one to avoid regret?
I can understand the difficulty overcoming regret when past sins have hurt others. Seeking reconciliation would have to play a part. There are some good resources at:
http://www.peacemaker.net
I know I haven't arrived in this regard, but am thankful for a merciful God.