I don't have a lot of time to respond as I'm home on my lunch break.....but I want you to know that I feel for you so badly! Affairs hurt, regardless of the circumstances. Whether it be a one night stand or ongoing affair, I know the devastation that it causes.
I think, though, that you would benefit from taking the focus off of your A. As you still are or you wouldn't be thinking so much about how he's trying to be "good" for the OW.
You know what - his affair is not about you. It has nothing to do with you. Affairs happen for many reasons, but it's always the cheaters choice to do as they are. And when it comes right down to it, I don't believe that any addicts are truly happy. It doesn't matter who they are with - they have a void in themselves that they continuously try to fill. And sadly, they are trying to fill that void with the wrong things.
I am so sorry that you are going all of this. I don't know how you can do it. I am amazed at some of the things that we go through for our spouses and the love we have for them.
But please, work on you. I truly believe that you deserve better than this - and I think deep down in your heart, you know that as well.
Sending lots of (((hugs))) your way.