I'm sorry, Mike. I wish I had something to say that would make it even a bit better, but truly.. I have nothing.

I hope that you and Amy can work things out, but if her heart isn't fully in it.. well.. I had something similar happen to me, and it was like someone let all the air out of me. I was just flat, not mad or angry, just flat. At least we weren't married and it was just her and me, no children.

First thoughts.. it sounds like something she was planning to do, not a spur-of-the-moment thing. See if she'll come over and talk to you, or at a neutral location, or over the phone as a last option. In my opinion, she owes you an explanation at the very least. If you can do your best to just listen, rather than try and have a discussion while she's talking, it might give you some insight at least. If she was thinking about it beforehand, she probably has a rational (maybe not to you but at least to her) reason for leaving.

Good luck.. i'll be hoping (and praying) for the three of you.