Finding what works for you also shows what doesn't. Pat yourself on the back for ticking one off the list.
Reassure your children that they don't have to choose between you and their mom. That you love them. And define boundaries.
If something isn't working then try another tack. Leave something interesting out. Stay within sight. Don't hover but just be around. Even the greatest resistance softens with proximity. If going to her isn't working, let your daughter come to you.
Make cookies or some other activity by yourself. Let her decide if she wants to be part of the action. And try seeking out Smiley's Person for tips. He has young children, too, and could be a good sounding board.
After the emotional trauma everyone is lost and hurt. Give yourself time to heal. Maybe even.. *gasp*.. seek counseling. My friend would push me, "Kathleen, if you broke your arm, would you set it yourself or go to a professional, a doctor to make sure it healed right? Going to a counselor is no different."
Everyone has to the process a divorce. Better sooner than later with someone who knows their stuff.
And remember.. You are the best. You are an incredible dad, excel in your field and are the bastion of honor.