This happens to me when I rarely open up Facebook. I'd see someone I was obsessing over in the 10s, and now I just wonder what I was ever feeling with them. It's not like something happened and they're massively different, they're more or less the same. Really the world changed a lot and I'm not the 
I used to be.
I'm not dating anyone new now. But if I had to judge someone as hot, they would have many of the following characteristics:
- left of some soft (Marxist, Anarchist, hell I'll date a decent socdem)
- mask wearing
- vegan
- high empathy, worry about the suffering of others
- reader
- actively organising something in their community
To be honest, I had a pretty basic taste in dates back in the day. If anything, this should be a self-crit.
I get vibes of someone with a psychotic disorder. Sounds like they needed help, though I don't mean to imply you needed to be the one to help them. I think you made the right choice; just hope they can someday get the help it sounds like they need.
Yeah I eventually got that vibe too and had no idea what to do. There was an instance one night where I got about 150 text messages in a row, sometimes of repeated numbers or people's names. It got scary.