CC, I'm sorry it's playing out this way. Of course, it's your fault. You are suppose to tie them up put the phone to their ear to speak to him. He doesn't get it...
You could suggest therapy and see where it goes. Hopefully he'll listen if you suggest that it might bridge the gap between him and the children.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.