If this is all true sorry man. I think you already know that it’s over, and if I were you I would confront that dude and stand up for yourself. Don’t let her use you like a toy she can manipulate around because you are her husband. Punch that dude in the face bang her friend and get a lawyer that deals in unfaithful divorce, it helps in a judge understanding the situation so he can make the best decision for the children.