Pegasus - I do not have alot of advice as our sitch's are very different. I do want to say you have been very good in controlling your frustration, hurt and anger during all this. You have let H know that you think you can work through this and he seems willing so that is a start.
I would try and let the OW thing go, it seems your H has and conversing with OW will not achieve anything it will just give you more doubts and more questions so I would be inclined to leave her out of it.
I would now be happy at home and act as normal with H and try rebuilding your R. If H is willing too he will see you moving on and it will show if he starts to move on with you. You can only control your actions not H's so make your moves and see what reaction H has and then act as you see necessary.
Oh and maybe not tell your friends too much more if that upsets H, at least then he will know you are listening to what he says and acting on it.
I know it is hard with a young child but maybe try as best you can to make an effort around home with the housework and getting as organised as you can so he has something pleasant to come home too. It's just that you mentioned the house previously so that is a little thing that must bother H on some level...
