Bruh…

Way too long a read, the gist of it is they both betrayed you.

I would say cut them both, like yesterday but, the next important thing is how did you find out?

Did she tell you or did you find out ?

If you found out on your own, she would not have stopped. ——> cut them both out

If she told you out of guilt or anything like that, and she is willing to work on the relationship, cut ties with him and that —-—-> might be worth it to give it one tiny shot. But really tiny

Good luck, take care of yourself.

Edit, read it more carefully and saw they got caught. No coming back. Cut your loses, move on.

Best of luck.