Infidelity Support Group
Any relationship in which one partner engages willfully in sexual relations with another outside of the partnership is considered to have experienced infidelity. This breach of trust is often traumatizing for the faithful partner as well as the relationship, and support is often needed to heal emotionally and to decide whether or not the relationship should continue after...

Wishing you well.
First you need to recognize the value in yourself and not leave it up to someone else to determine it for you. Perhaps a counselor can help you with your self esteem and give you a better perspective.
I agree that if you want to stay together you need to seek some kind of counceling. Maybe a pastor?
Your value or worth is never in question when you are cheated on. This is the result of the character of the cheater. You just need to make sure you don't attract or pursue guys of poor character.