at first I was very shocked I did not think he was the kind of person at all
The media like to portray men who pay for sex as either sleazy dirtbags, or wealthy arrogant wall street types.
The reality is that there isn't a "type" of man who pays for sex, just as there isn't a "type" of man who likes cycling, or a type who enjoys watching football/Top Gear/Bake Off or who plays Xbox.
My clients cross all social classes, all races and religions, all adult ages. I've had clients who are heads of for major international finance institutions, and clients who have part time jobs at Aldi. I have had a few incredibly lovely clients who I would cheerfully see for free (and one has been promoted to FWB status.) I have had a tiny handful who I never want to see again. But the vast majority, say 99%, just fall into the "average" category.
Leaving all that aside, it seems like he's still lying to you and minimizing what he's done. You might want to say to him that he either respects you enough to give you the truth, or you're done.
Blaming it on porn, LOL. The truth is, he wanted to fuck someone different and he didn't want the time or trouble of looking for a hookup for free, so he paid a sex worker. If he can't own up to that, and be realistic about the chances of remaining monogamous for the rest of your marriage, then I'd say adios.