A popular myth is that an affair always ends the marriage.
While some marriages do end when there is an affair, the reality is that any couple can survive and grow past an affair, if they are committed to ending the affair and cutting all ties to the person who was part of the affair, the other spouse has to deal with the sense of anger, betrayal and the other emotions that come with this territory, the spouse who had the affair must genuinely apologize for the harm caused, trust has to be rebuilt, and then emotional intimacy needs to be worked on by both partners to heal the relationship.
The shame and guilt associated with affairs make it feel that there will be no support, advice or help from relativies and friends. And yet without help, your odds are decreased of getting through the maze of recovery in the most expedient and constructive way. Sometimes, especially with this issue, help may need to come in the form of a professional specifically trained to help couples meet the challenges after infidelity and affairs.
However, this often requires some skillful facilitation from a therapist specifically trained in dealing with issues after infidelity occurs.