Thank you for a long good answer.
I'll add my own personal answrr
Carrboneous says the feeling of non-safety has only recently begun to fade. I will speak for those for whom it has barely faded at all. We have learned that the world doesn't care about us and cannot be trusted. We have not unlearned that lesson yet. I do not trust a single country other than Israel to give a damn about me, my family, or the Jewish people when push comes to shove. Individuals with consciences? Sure. But nothing beyond that. When the west wasn't actively involved in the murders (ex: Poland, Ukraine, Romania) it was turning back refugees (ex: England, United States, Switzerland - for bonus points, Switzerland also built the crematoria and stole money from holocaust survivors after the war)
My family tree is skewed. Just imagine a literal tree and then lop off almost all the branches on one side. My mother's side fled to America before the holocaust (in the wake of pogroms) . My father's side did not.
My grandmother survived because she was in France. Until her dying day she carried the guilt of having sent her younger brother back from France to visit their parents. Germany invaded. Everyone was murdered.
As for the horror of it- I only ever read about the holocaust on a single day of the year. I can't the rest of the time. It is too horrible to comprehend. Not the deaths, the cruelty. Mengele, among other experiments, boiled people alive. They smashed babies against rocks in front of their parents because they could. Thinking about it makes me sick to my stomach, sometimes so much I can't function normally as a result, so I avoid thinking about it.
Another note: carrboneous says 12 years if we're being generous. The first 7 years were a slow boil of antisemitic laws, nothing we hadn't seen before, nothing that indicated how bad it would get. Then Germany invaded Poland, wwii and hell began.
It accelerated exponentially. By 1943 it's estimated more than a million Jews were killed -which means five million more were killed in the next two years..auschwitz was killing 5000 a day by that point, but it took them a while to build up the capacity. (the allies of course refused to bomb the train lines to auschwitz. See above. Trust no one.)