I'm truly sorry 'bout your relationship went sour..
I understandable, your hubby wants move on and throw into his own new seed.
You'll be okay and be strong supportive for your children comes first... of course it really aching your heart and think about your children. No matter what.. Maybe he'll look back over his shoulder and condiser willing do anything change his mind and be there for your family again..
I've seen other divorce goes through hell but isn't easy "rough long haul walk".
Which Good thing, what I've seen AD'ers whoever still supportive you as friendship-moral... That was great!
*Chin up* you'll always great mother fits in your children needs to meets. 
