I am in my late 40s and I remember always having either a sour candy or a fireball (cinnamon jawbreaker) in my pocket or mouth when I was in middle school.
Similar age and ya, I remember sour packets being popular in middle school. Can't recall the name, but it was similar to the artificial sugar packets used for coffee, except it had a mixture of sugar and citric acid (the "sour" flavoring) in them.
I don't think so. I recall Fundip being in large pouches with the pressed sugar sticks for dipping. These packets were a lot smaller and didn't come with the stick.
Any chance the candy was mexican? Cuz that opens up a whole world of possibilities. Limon 7 packets, pico packets, not to mention a whole suite of Lucas powders.