FWIW- my H planned his exit for a year, and 12 hrs after he verbalized it, panicked and had second thoughts. The reality can hit them hard. I'm willing to bet your H is grappling with guilt, too. Your D17s reaction to him is just the first taste of the consequences he will have as time goes on.
Hang in there- i would bet he's struggling right now, too.
Me: 39 H: 45 Second marriage for both H left 12/2013 M:4 T:5.5