It [censored]. I know that day is coming for me, and I hope I can react with strength and grace.
Just try to keep your chin up. There was nothing else she was going to say during your MC. Of course she thinks it's done, she filed for divorce! Remember that while filing for divorce is easy....actually BEING divorced is not. Just because it's what she thinks she wants now, doesn't mean that it's what she will want in 3 months, 6 months, a year, etc.
Just keep going down your path. You can see that it's having some effect on her. Be the man, be the father you want to be and you'll come out ok with it without her.