"He used to push me more to going out and seeing my friends rather than making it hard and isolating me.
My biggest criticism was the amount of attention his work and networking took."
I'm sure you're not rose-tinting it, tom. what you say is really interesting. The things that jump out for thinking about are the fact that he is clearly driven, an achiever and has a will to move on to bigger and better all the time. He has 'his eye on the prize' as my mum used to say! Also that he spent a lot of time away from you 'networking' and encouraged you to have separate life too. This isn't totally terrible but it does speak of someone who compartmentalises massively. Lots of people would take their partner with them for such occasions. If you combine a compartmentaliser with someone who's entitled in the driven, thrusting way you describe, you get someone who is very very vulnerable (!) to infidelity generally. Him pushing you to seek out your own social circle isn't necessarily trying to do right by you, but fits totally with someone who doesn't want to feel bad about himself. He wants you to take responsibility for your own social needs, so he can continue fulfilling his own in whatever way, rather than include you in his.
From what you've described I think he is a man who wants to do whatever he wants, and that includes having a wife who is a source of stability and fidelity and loyalty at home. I don't think from your description, he has ever been prone to sacrificing anything important for anyone else. It just depends whether you are prepared to fit in the slot that he wants to fit in. It's the definition of entitled. When you say messy, I think 'lives how he likes and expects others to clean up after him'.
And I wonder if he can see it. That's why, I think, when you sit with him there is an undercurrent and understanding that you will get back together. Because that is, all in all, what is best for him. So that is what he wants and expects. And that is how he has lived his life. Purely from his point of view, with an expectation that others around him will fit in to it. And perhaps they have tended to.
Let's not forget you discovered the affair, he didn't tell you. If this was an aberrant, one off thing that had completely shaken his sense of self that he could see no way out of, it's more likely he would have told you, however difficult, to try and find a way through it. As it is, I think he has always approached things in this way, it is you who had blinkers fall from your eyes. I think he would have to completely want to alter the way he has lived until now and fundamentals about himself and his character. It's not just a dynamic about who has taken most control of things, it's sort of a much larger version of that. I think he has always been the protagonist in this marriage, and in his life. Of course everyone sort of feels that, but most people learn early on that other people are real and as central as they are, and they cannot have everything or everyone they want whenever they want.
'Respectful' is all well and good and easy when the other person is not restricting you in any way (because they don't know what's going on). I know it is horrible to think about but I really think he has probably always lived this way, doing whatever he wants away from you, and that is why, unless he can own that ultimately, admit to it, and find a new, genuine, humbler him at this late stage of his life, you may find yourself in his sidecar again.