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...
https://www.dailystrength.org/group/cheaters-anonymous
This is mostly a general Infidelity group that have a lot of betrayed spouses on it, so they would be good for you to read up on to realize what people on the other side go through, you aren't as likely to receive much help other than the old Bob Newhart skit to "Stop it!" In general, of course. Hope you find the help you need.