I had a breath holding resonant reaction to your story as if I was reading my own psyche. In about the same timeframe with virtually identical observations I found myself in your writing. The only circumstantial difference was I lost a son to schizophrenia instead of a sister to ALS.
The motivation for my comment is the line I highlighted. I have come to believe, for me as a hypothesis and interpretive filter in my life, that we are far less rational creatures than we convince ourselves we are — throughly confusing story and myth creation for what we are self-convinced is reason, “reality”, fact and pattern. We are not that different than Homo sapiens from “primitive” cultures from 500 BC we tend to scoff at. We are doing forms of superstitious creative story generation.
Yes, if this view has some merit it offers us opportunities for modifying our reactions, calculation of meaning, attitudes and motivations. And, it has the downside potential to create fears, division, misery, judgement, wars, prejudice and violence to ourselves and others not driven by rational facts or reason at all but instead just “stories” we have fabricated.