I'm not sure if you've already heard this a bunch, but it needs said often for anyone who has this experience:
People without face blindness constantly struggle to recognize and remember faces. The idea that most people recognize anyone and everyone they've previously met (and remember their names!) is a complete myth.
I've gotten really good at remembering names and faces though practice and techniques like writing down everyone I meet in a notes app, and I still have like a 60% success rate on second encounters after more than a week.
My solution for the other 40%? If I'm not totally confident someone is new to me, I introduce myself with "Hi! Apologies, have we met?"