Going back to revisit the anger phase you are in, we all hit that place at one time or another. I had a very wise mentor who framed it quite well for me, Anger is ok to feel, just do not get stuck there, you can as Vapo touched on, use it as fuel to get you past a part of you holding on and it will land you over on the other side ... just understand its all part of this marathon, part of the process, part of the growth but you have to harness it and use it as the fuel its meant to be.
As far as her actions ... they will never make sense. I have read quite a bit on how they feel during this phase (if they can remember much at all looking back) and seems more times than not once they are past all this and on the other side of the tunnel the collective is "It wasn't that I was unhappy, I just thought I could be happier and I was mistaken" .... so understand it has NOTHING to do with us, we are simply collateral damage in all this, it stinks but that's all we are at this point and you will have to allow her to make her mistakes as she chases this euphoria she is certain exists.
The trick is to not allow it to make you bitter, to somehow come out of this a better person and better father for your children. As a result you will be a better man and either she will at some point wake and realize this .. or she wont, its out of your hands ... but what is in your hands is how you progress, how you grow, and all these lessons you will learn along the way and how you apply them not only to yourself but with others.
