I have a few thoughts based on many conversations I’ve had with lgbt people who’ve come out later in life. Straight people rarely question their sexuality and imo, if he’s turned on by male gay porn he is not straight. There are different kinds of attraction. Romantic, intellectual, relational, sexual, etc. Maybe he’s now still attracted to you as a person but not sexually. Coming to terms with one’s sexuality has a pronounced affect on things.
He may have participated in sex and romantic things with you because he thought he should, didn’t understand that he didn’t feel how straight people felt, etc. It’s entirely possible he didn’t know/repressed things so hard that he didn’t put things together. Religious indoctrination is powerful.
Will he swing back? I hear the hope in that question. I had that hope. No one can tell you that, not even him. Just know that I’m 2 years post disclosure, I waited for 20 months for her to figure herself out hoping for her to find desire for me. In that time I’ve become depressed, angry, resentful, miserable, attempted suicide and feel generally disgusting, unlovable, undesirable and empty. Waiting for your person to choose between you and a different life and watching and listening to them reject you on a core level of your being will cause harm you can’t understand without going through it.
No one needs to have sex to know their orientation.
Please believe him and make your decisions based on whether being married to a gay man in a sexless, loveless marriage is what you REALLY want.
All the best to you!