Many of us are shame based and have made lots of decisions based on shame and jealousy and anger.
We have to learn to forgive ourselves and make ammends. Making ammends doesn't always mean telling the person you feel you have harmed or apologizing to them. That can make matters worse and you don't want to hurt someone further. Maybe just talking to your friends is making ammends. Changing future behaviour can be making ammends. With phones and facebook it is really hard not to spy on someone. I have done it. Had her voice mail password and her email password and used to check on them all the time after we had broken up. Felt horribly ashamed of that behaviour. I had to work on my own self esteem and insecurities and learn to forgive myself. We are not our behaviours. Relationships are very hard.