I wanted to throw one more thing out there, I realize that I don't sound like I am advocating 'saving the marriage' and I didn't want to come across negative in that way. But the marriage is over. Your marriage is over, my marriage is over, and what I want and hope for you is that your truly understand you are worth more than sitting around waiting for his scraps. Maybe there is a chance for a 2.0 in the future but the only possible chance for it is to let this one go. When you finally can let it go you will realize that no matter the things you did or didn't do, you don't deserve his actions of walking away and being with the OW. You deserve better and unless he puts real work into fixing his issues (doesn't sound like he has any desire to do so. Probably like mine who thinks its all my fault and nothing is wrong on his end!) then there is nothing there that you should be hanging around for.
You deserve better. Hold your head high and stop holding all the blame on yourself. It takes two to tango and he is running away from his accountability and responsibility and that is not a man worth chasing. Maybe if/when one day he does face those issues then you have something worth your interest.