Oh, the situation is really unpleasant. But I want to tell you that it’s better to put up and let her go. Since the person who has changed once will change again, I guarantee you…
The main thing you should do now is to give yourself time to let go. It will be difficult, but necessary. Understand that you deserve love and a partner who will not cheat on you.
Let her go, let her meet the guy she cheated on you with. Move on. Perhaps you should get carried away with something like music or painting. Believe me, it helps a lot.
I also suggest taking the initiative into your own hands and file for divorce yourself.
Start life from scratch, you have already tried the other side of life with it.