I feel you, Pommy. I feel you 110%. My only recommendation at this point is to breathe and take your time. Give it a week or so and see how you still feel. You can't control him, you can only control you, and making any long-term decisions when your emotions are running so high is probably not a great idea. After I found out about the extent of my H's affair, I had a call with my coach (who already knew, because H had had a call with her and told her everything). She kept the same DB-ing advice from prior but added that I should take some time before making a decision since I was quite upset.
Hope you're doing ok.
Me (46) H (42) M:14 T:18, D9 & D11 4/19 - 12/19: series of escalating BDs 9/20 - present: R and piecing