Keep breathing and keep thinking straight and with your kids as the priority....great job there. It's very hard to do when your heart is in your stomach and your head is spinning, you've stopped eating and sleeping like a normal person. So truly good for you for keeping it together.
Next, I think you both need to realize she has to make her happy and you need to make you happy, then you can come to the table and talk about the relationship. When each of us is the main source of happy in our own lives, it makes it much easier for everyone else around us....there's less pressure on our loved ones to make us happy, which they can't really do like we can.
Hang in there. You are doing amazingly wonderful. I am very impressed. Today, you are my hero!