Read your own tag line, honey:
May God fix this marriage and the man I married, if you can't just show me the road I should be on.
You've just been shown the road you should be on. You are living with an actively cheating, remorseless man. What would you advise your sister/BFF if she came to you with this information?
What should you say to him the next time he brings it up? Nothing; because there should not be a next time. I'm speaking from experience; I let the X gaslight and bully me into staying in a situation where I felt I had to monitor and surveil his every action; I should have left after the second time I caught him. Hindsight is 20/20, and I'm trying to give you the benefit of my improved vision.
Stop second guessing yourself and start putting your ducks in a row.