It's good that you are communicating better with your W.
In my opinion, unless OW is totally out of the picture, you will never have a chance to save your M.
Call her anything you want, but as long as anybody other than your W is fulfilling your emotional needs, I think your heart won't be in working on your M. Just my opinion. I'm not trying to be a bit**. It certainly sounds like your W could give a whole lot more attention to your emotional needs also.
You really do need to blow off OW entirely and not worry about how she will take it. In my opinion, she can't be all that great if she is hanging around a married man.
Why not approach this in another way? Why not try and meet your W's needs and ignore her when she is bitchy. Maybe she will begin to treat you better. You think?