Ok, I finally got rid of my boss so I can finish what I wanted to say.
Emily, just because your H says he wants a divorce and says he wants to be with this OW doesn't mean it is time to give up. Even though there isn't any other woman in my situation, my H has hollared divorce to me for the last 17 months. I have not seen the first bit of paper, he has not made any calls to any lawyers, etc... I have not given up yet. As odd as it sounds, sometimes I wish there was another woman in the picture, at least then I would feel I had something to fight against. You can win if you really set your mind to it.
Your H says he likes this OW more than you, right now he thinks this way. With her, he has no responsibilities. He is being selfish. Let him be with her right now. If he came back to you then he would be thinking about her and things would be the same. Let him get her out of his system. (I know this is hard for you but you have to let go) Put all your focus and energy onto yourself and your girls. Don't let him even think you want him back home.
With the phone calls either from him, the OW or you calling them....that needs to stop. It is like you are in high school and calling around like that. Show him you are more of a woman than his (whatever you want to call her). Show him that you are mature and don't need to play games. That is all it is to him. He knows he has you so there is no challenge there. Right now with her saying she doesn't want him it is a challenge for him and he is eating it up. Make him think you are a challenge too. When he calls, don't answer. Don't call him either unless it is an emergency with one of the kids. Let him think you have moved on.
As weird as it sounds, you will not get him back until you let him go. He is playing all of this up. He tells you all this stuff because he knows it will get you riled up. Go along with him. If you do happen to be talking to him and he starts in with divorce, then change the subject or get off the phone. Very nicely say the baby is crying and you have to go or anything that doesn't pin you as being negative. Be happy and upbeat when/if you have to talk to him. He won't understand how you can be happy with him being gone.
Now, to the question if he files is it over...I said no and I really don't think it is. A divorce is just a piece of paper. You got married because you fell in love, you can fall in love again. When you fell in love the first time you were not a clingy, crying basket case were you? Ok then, why would he want to come home to one of those? You need to stand up and fight for your man. I don't mean that literally. Become that person he fell in love with in the first place.
As I said before, you have to let him go to get him back. That is what I have learned. I am letting my H go (not too far) and it seems to work a little bit. The only time he yells divorce anymore is if I get to asking questions about us. If I lay low and talk to him about the kids or something to do with the house then things are fine. He talks very nice to me and we get along. I learn from my mistakes and you can do the same thing. Write down what you do that seems to trigger him to get mad, then you know not to do that again.
I hope this helps you out some. Just remember, it is never really over!!!!