I wish I had some words of wisdom for you. My evening was pretty crappy, too. I hope, though, that tomorrow is a much better day for you. I do understand how you feel. My H has been out for almost 3 months now, and though his OW appears to be out of the picture now, it still has not brought him back home. My oldest D is 9 and has a hard time dealing with all this, I think. There are days she is good and then there are other days that she is downright defiant and also crying at the drop of the hat. I feel so bad for her. My youngest is 2 1/2 and because she is so young obviously doesn't know or understand anything, but I think finally in the last few weeks or so that her tiny little mind has really realized that he is not here. When she sees him she just lights up and when he goes to leave she won't let go of him and just cries for him. It is the most heartbreaking thing I deal with. I don't know how he can stand it.
Just try to keep focusing on yourself and the kids and as everyone else said, "one day at a time." Hard to do, believe me I know.