I thought I would respond here; at the 3-4 year mark, pretty much 3.5 years after BD, my H again seemed to be turning back towards me, I again thought that the tide might be turning. He had had one such episode a year before, much more of a breakdown, at the 2.5 year mark, when I really did think that the worst was over, I was wrong.
The forum had just started then, about 6 months before, and I remember titling my first thread "somewhere in the middle" -- I laugh now, because I honestly thought I was somewhere in the middle of this mess, and that I would, in a few years, just say that yes, he did that the first year, that the second, and was "done" by the nth.....
This was one of the points where I again saw "him", where I could see him reaching, reaching reaching -- coming within a hair of reaching out to me, and then pulling back again.
He talked a lot at that point of feeling guilty, started saying he was going to be around a lot more (the r with OW4 had just finished), even asked more about me, that kind of thing.
It didn't quite work out that way, of course; a week or two after talking to me like that he announced that he was off to the other side of the world "for a few weeks"; taking great pains to say that I was still his emergency contact, and saying that it was all for professional reasons so that he could provide for us, that of course didn't happen that way. He did go away, it wasn't with an OW, but it was probably to feed what I didn't at that point fully understand was an addiction, and of course it was physically running away rather than facing a problem.
And yes, 6 months later later we realised there was now an OW5, he had a "new" professional venture that seemed very dodgy (turns out it was), and he was again closed off, angry, all that.
That may have been what the articles call peeking out of the tunnel, possibly seeing the damage and not being able to face it, call it what you will.
It was when I really was able to put into practice the art of listening and responding rather than reacting; it was something I had been working so hard on learning how to do. So I did, if I go back over how I spoke to him then I wasn't angry, I wasn't completely agreeing with everything he said, but I think I did OK.
I did, however, think that perhaps he was showing some concern for me and my difficulties with the children when he showed some understanding of the difficulties that one S had, but again that fell short of the mark. I was quick to give him any opening, though.
So it was one of the many dips on the rollercoaster; for me it was yet another exercise in learning to deal with this all.
Not long after the conversations I related above a close friend died; we spoke a while after that and that was the time that I did, for the first time in nearly 4 years, tell him that I did love him. He had tears in his eyes then, and told me that "I guess you never stop loving someone". I didn't know about OW5 yet then, we found out only later, but all that was yet another point where he may well have looked, thought again about us and our family, but in the end he still chose another life.
Not, I stress, because he was "cooked", but most likely because he still couldn't face himself, or believe that I wouldn't punish the h - e - double toothpicks out of him. He still thought that a "someone else" would solve the problem.