He’s so deep in the fog that he feels justified to do it!
Let's talk about "the fog" for a minute. Yes, I do believe cheaters become "foggy" in their logic, caught up in their fantasy and obstinate in their resistance to reality. Further, I believe they're capable of snapping out of it, sometimes suddenly and with no real understanding of what the hell they were thinking at the time. But there's a hidden trap in relying too heavily on "the fog" as an explanation for the sudden change. We can fall into an empathetic visualization of our WS, lost in the dark, surrounded by impenetrable fog, and needing our help. "The fog" begs us for sympathy, for caring, for patience at a time when we can LEAST afford to exercise such.
Your WH wasn't "foggy" when he sat down and searched for that website. He wasn't "foggy" when he opened the first chat window. He wasn't "foggy" until after he met an AP and decided she was so much MORE than just another dime-a-dozen cam whore. It wasn't until he started participating in the fantasy and until he had become emotionally addicted to the biochemical cocktail that he became "foggy".
This was what I didn't understand sixteen years ago when I was in your shoes. We've been married for thirty-seven years now, and six years ago I caught my WH on a Craigslist binge lasting nine months featuring multiple OWs and various degrees of emotional entanglement. But ten years prior to that, I caught him out on interactive porn and only two weeks away from meeting up with a cam whore he believed he was in love with. He had his trip planned and believed I was still in the dark.
The day I busted him, I saw an attorney first, then called him home, tossed his messages and his dick pics down in front of him... and told him I wanted a divorce. BAM! Fantasy bubble popped. Reality slammed home. Fog cleared. He freaked. He understood in a single second that he was going to lose everything; his wife, his family dynamic, the respect of extended family and friends, half his worldly goods, etc.
What shocked me was that this was such a departure from the man I thought I knew. I was actually afraid of him in those moments of confrontation. Not because he was a threatening sight, crying and huddled as he was. But because I DIDN'T KNOW THIS GUY. I kept my car keys in my hand and my body between him and the door in case I needed to run for it. Later, like almost every other BS, I started looking for answers, in books and online. Mostly what I kept finding was pop-psy based on "unmet needs" and "midlife crisis" and how people could become unhappy enough to do these bizarre things. I discovered how the biochemical cocktail worked, saw it in action as I asked him to show me the websites, saw the electric vibration in his hands as he tapped the keys and the dilation of his pupils as he took in the screen. And I allowed my empathy to rule the day. I bought into the "unmet needs" jargon of pop-psy shysters. Upped my wife game, became a soft place for my WH to land, the soul of support. For his part, he saw the doctor, popped some Lexapro for about six months, and within four years was out searching for pussy again. 
Because it was never about being "unhappy". It was never about "unmet needs" or a crisis in the midlife. Cheaters cheat because there's NOTHING in their character stopping them. There's a gap between their stated values, like fidelity and honesty, and their actual deeds, cheating and lies. There's a "but..." in their values system. ie. "I believe in fidelity, but... not if I'm unhappy.". For normal people, we surround our truest beliefs and virtues with a ring of boundaries. ie. "I believe in fidelity, so... I don't put myself in compromising positions with the opposite sex." Our values don't have a "but...". They have a "so..." which represent the boundaries we've erected dictating our behavior and protecting our core beliefs.
I know I've traveled a pretty long way, but here's the point... Your WH's fog is NOT the cause. It's just a symptom. The cause is his flawed character, a character with weak and permeable core values and no boundaries surrounding them. And unless he's had a brain injury we don't know about, this was ALWAYS who he was at his core. You just didn't see it. Neither did I.
We don't cause this. Nothing we do (or fail to do) can cause another person to suddenly abandon their own core beliefs. We don't have that kind of power. The beliefs weren't really there. They were lip-service, given from the kind of person who blends in but who is never really fully vulnerable and fully known. These kind of people always hold something back, but it's not until some kind of crisis, like adultery, that the facade is challenged and the flaw becomes visible.
Sweetie, he's not "broken". "Broken" assumes that he was whole before and now he's shattered. That's not what's happening here. His behavior has caused that carefully kept facade to slip. His lack of integrity is on full display, but this isn't a recent loss. His integrity has ALWAYS been lacking. We don't see that until the crisis when they can't keep up the facade of normalcy anymore. He does not share your values and he never truly has. People who BELIEVE in their own core values cannot be shaken from them. If you really believe in fidelity, you can't be MADE to cheat. And you certainly don't go looking for it.
This isn't a change... it's a revelation. He has revealed himself, and he's miserable because the facade has failed. He's exposed now.
Sixteen years ago, I didn't understand these things. My empathy got the better of me. I believed that my WH's behavior was an aberration, not a revelation. And ten years later, he was out on a binge, fucking things that would make most men barf at the thought and featuring himself to be "in love". THAT is where unearned empathy lands us.
Save your empathy for someone who can be helped by it... YOU. Even if your WS does make it "out of the fog", it's still not enough. People can (and sometimes do) remediate their flawed character, but they've got to see it and want it. These are the truly remorseful ones, broken not by confusion or lust, but by the reflection of their own true selves in the mirror. These are people who will do ANYTHING to stop being that pathetic creature who uses others as narcissistic "supply", people who WANT the core values they've always pretended to have.
I'm sorry I can't give you more hope. But the hope you're still clinging to is actually hurting rather than helping you. Like you, I had many good years with my WH before the cheating. We had our ups and downs but I chalked that up to everyday life. Like you, I thought his character was solid... until I had evidence in hand that it wasn't. I was completely blindsided by the idea that he was even capable of cheating. I thought I knew him. But when I sat back and looked at him dispassionately, clinically, with all the evidence on the table, I could no longer deny that this was who he REALLY was and who he had always been. That capacity for true deceit had laid dormant for two decades, but it was always there. I just hadn't understood what it meant. It was there in his need for attention, his overly friendly demeanor with women, his grievances at authority, his tendency to exaggerate, his inability to resolve conflict, and in so many other ways. All these frailties of the ego which made him dependent on others for validation were things I had always found endearing. And there's my codependency showing 
He gave me purpose. I intuitively filled those gaps for him with understanding, emotional support, and a pretty much endless kibble supply.
There comes a point though, where our old and familiar kibbles aren't as tasty, where our external validation is no better than getting it from your mom. This kind of psychology cannot be filled. It's not self-fruitful. It does not understand that it is faulty.
There's NOTHING you can do to fix that. The only one capable of repair is the WS himself, and as I said earlier, he has to see it and want it more than anything else in life.
I'm sorry, truly I am. You are obviously a very sweet and kind soul. But the only thing which snaps through the fog is Reality. And even that is not enough. The WS needs to make real changes... and many do not.
((hugs))
[This message edited by ChamomileTea at 1:09 AM, February 9th (Tuesday)]
