IB, I'm so sorry you are feeling sad. I wish that I could make it better for you, but you aware that this is another step in recovery and those feelings will wash over you periodically when you least expect them to. I promise you, that in time, those sad feeling will be appear less and less. It's better to work through them as they hit then to side step them.
Your xh doesn't realize, nor sad to say, care right now about how his children are feeling. I'm sorry to read just how out of touch he is with reality. I will keep your daughter's fiance's family in my thoughts and prayers.
Irish, you are not alone...we are all here for you. We all have traveled or are traveling the road that you are on and understand completely how you feel. I'm sending "hugs" today. I hope that you feel better soon.
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.