This is not your fault. This reflects poorly on him, not on you. You have been trying to save your marriage and protect your kids, that's the most admirable thing you can do.
Don't allow him to tell you when things are over. Feel free to disagree, feel free to pursue your own timeline and your own goals. Remember -- don't believe what they say.
My W told me she wanted a divorce. I asked her if there was any chance of reconciliation and she said "absolutely none, I'm done".
She's still here.
Accuray
Married 18, Together 20, Now Divorced M: 48, W: 50, D: 18, S: 16, D: 12 Bomb Dropped (EA, D): 7/13/11 Start Reconcile: 8/15/11 Bomb Dropped (EA, D): 5/1/2014 (Divorced) In a New Relationship: 3/2015