I met a man recently who can't seem to let go of his past mistakes. They haunt him. His regret consumes him. He is tripping over things that are far behind him. His expectations for himself should encourage him to reach for high goals, but instead they have become a magnifying glass for the past.
You are not expected to suffer your entire life for past mistakes. If there is someone in your life (including yourself) who is trying their best to change, let them repent. Promise them you'll help them bury their sins and mistakes deep by never bringing them up again. When it comes to mind, acknowledge it silently and then dismiss it. You cannot allow your past (or anyone's past) to hold you hostage. Refuse to allow yesterday to ruin today and tomorrow. I promise you God cares more about the future than the past. Forgiving yourself and others is the key to real peace and freedom.