That's totally understandable. George Patton said, "Plans change upon contact". Meaning, we can have the best plan in the world until we run into something unforseen. This would probably qualify as an unforseen.

You are right to feel you need to know the truth so you can make a decision, I still think you should wait until your emotions subside a bit so you can have the discussion, if you choose, while already having made your decision, eg; if the truth is that H is seeing the OW, than I will __________, or if the truth is that nothing is going on, than what will it take for me to believe him; greater accountability, no more overnights. Whatever it might be, I think you will be better served if you are able to walk in with a set plan in your head. Rather than trying to work from the disjointed state you are in at the moment, (and will possibly be in for a day or two).