Callie, let the children know that this must be very difficult for them knowing how much they love their daddy. Daddy is sick, not thinking right. Most importantly let them know it's not their fault. Sometimes daddy will call and sometimes he won't be thinking right to call. Let them know that you will always be there for them, hoping and praying that daddy gets better someday.
Most of all just listen, and validate their feelings. And lots of hugs.
Huggs to you,
NH7