Forgiving someone who had done you wrong in the past is hard, we often carry this burden for a long time thinking that it is the best way to cope with what they did so that we will never reconcile with that person in the future.

Forgiveness doesn't mean reconciliation with the person who hurt you, it mean reconciliation with yourself. Forgiving other people means moving along with life without  "that" painful memory but forgiving doesn't mean reconnecting with that person. 

Acknowledge that they've done you wrong, move along with your life without them and also as you slowly forgive them, you also need to forgive yourself.