What's the thought that's causing you the most pain? What are you going around thinking about this? List some if you can.
What are you making it mean that your h probably slept with an OW? What does it mean?
You are being triggered here. This is YOUR STUFF and it's yet another opportunity to do profoundly life-changing work.
But there is pain and there is pain - pain that something like this happened brings you to a grieving place, where you go through the stages of grief, feel your emotions, and come out the other end - better for it, accepting. Even if the "better" isn't something that manifests outwardly, it's inward.
And there's pain that you can continue to foster and cultivate by telling yourself stories and lies - "I am not enough" "He broke my trust, and that means that (whatever it means)."
Be careful to not keep that "dirty pain" - the pain we continue to foster when we're afraid - alive cause like everyone is saying, it can eat you alive.
Before you do ANYTHING I would encourage you to work with a coach (not a therapist who can keep that story going and going and going) who is trained in helping you work through the pain and MOVE ON.
When you are in a calm and "Clean" place, you can decide what is best for yourself, your marriage, and your family -