I get really angry when I read your sitch at the disrespect your W shows you. I can't imagine the feeling you have knowing she's spending the night with another man. I'm am really sorry you are going through this right now.
Having said that, how does that make you feel? You don't have to be nice to her! Actually when you do it makes you look weak. You don't have to do family time. Do things individually. It will help you transition to being a single dad.
I am going to be honest with you. There is no technique, thing you can do or say that is going to turn this around. You are going to have to go through the process and make some major changes before you have a chance of turning this around. When I say that I mean that once you learn to love and value yourself you will instinctively understand that there is no way you would ever allow someone to treat you the way she is treating you. Once you get to that place, she will notice.
It's a long difficult process with no shortcuts but you have to go through it to get to the other side.
