Such a sad story AS. So sorry for your loss. Although you did not know him well, had he lived, you may have in the future and are no doubt grieving what maybe could have been for him and for you. (((HUGS)))
As a child and youth therapist, I see daily examples of parents getting too caught up in their own stuff and the children being pushed aside like the break up of their parents doesn't somehow affect them. I am beyond grateful that my STBXH is putting his efforts towards being a good dad and a good co-parent. Despite his title of King Douche, he is only that as a husband but luckily, not as a father. It took some work on my part but I can honestly say that he and I are in a good place. We will likely never be "friends" but we will always be two people who share the most precious gift one could ever ask for...the unconditional love of our children. That is something I treasure and will always take the high road because of it.
Thank you for reminding us who and what should be our top priority in this difficult time. xo