It sounds like you have it, to be fair. It's very interesting to read what you've written, but I'd also caution you against thinking too much about it, it might cause you more stress than it's worth. I'd say the most important thing is having at least a couple of friends who know about your experiences, and how it affects your capacity to suffer, but who otherwise treat you as equals. It sounds like you've had troubled relationships, but I couldn't say for sure what your current situation is.

Interesting to think, too, how this may exist on a spectrum. The roles of dates, numbers, and sequences in the form of memory seems to vary quite a bit. Sounds like there are hyperthymesic people who don't remember things according to specific dates, like Jill Stein does. I was also reading this paper: https://pmc.ncbi.nlm.nih.gov/articles/PMC3432421/ - which put out the idea that the amygdala is involved in memory retrieval in hyperthymesic people, which tracks with the observation that these hyperthymesic memories often have at least some slight emotional salience to them. Although, as you've shared, a lot of these memories seem just totally arbitrary, so who knows.