I'm in year 6 of R. At this point in the game, the AP is never a thought in my mind unless we are discussing something about her related to the affair (and I can't remember the last time that even happened). I most certainly do not miss her, and you'd have to put a gun to my head to get me to do anything related to her in any way.
As far as looking back on myself, I find myself awash in emotions. Disappointment, anger, bewilderment, and even a sense of betrayal in the self-betrayal sense, all towards myself. Before the affair, I had it all, honestly. All I wanted in my life was to be a great husband and a great father, and to have a household that wasn't like the emotional toxic waste dump that I grew up in. I had a smart, beautiful, strong and talented wife who loved me unconditionally and supported my crazy dreams. I had two really amazing (in every way) step kids who appreciated me and never gave me trouble, my own daughter who is the light of my world, a dog, motorcycles, a nice house in a nice neighborhood, a great job that loved me... seriously, I could not have been happier.
And I blew it. I lost everything, and everyone that I loved and cared about was betrayed and hurt by me, so they lost some of their dreams too. That toxic childhood I thought I had left behind a long time ago, well... those things have a funny way of creeping back in when you ignore them. Hurt people hurt people they say, and that was true in my case.
I'll be honest with you, the burden of that guilt, the knowledge of the betrayal(s) you committed and the damage done, once you get out of "the fog" and reality creeps back in... it's too much to bear. It just is. I can see why so many WS's choose to just stay in la-la-land, because they can't deal with the truth. It hurts too much. It leaves you feeling soulless. Somehow, you have to find a way to deal with that which is too much to deal with. Some days it can feel like counting grains of sand, like an impossible task, but if giving up is not an option, then you have to start somewhere, and just ignore the fact that it's endless. You make it work.
What's changed the most is my ability to deal with stress and conflict, and moreover, my ability to love and value myself without a 100% reliance on others to make me feel worthy of the air I breathe every day. My wife and I talk things through now, even when it's tough (especially when it's tough), and the way we talk is healthier now. More listening, less blaming, more feelings, less definitions. I've stopped seeing myself as a victim (still a work in progress and it always will be for me, but I've made some good progress and I'm proud of that). I've learned techniques to help squelch the noise in my head. Although there's never been a greater gap between us in the marriage, in some ways, we're closer, more honest, and while love is no longer unconditional, in some ways, that helps makes it stronger, because we now know both the good and the bad of the relationship, and yet still make the conscious choice to move forward together.