Help! Pain between two teeth?!

Tough to say without looking at it, but it sounds like you traumatized the gums. If so, it's nothing serious and will heal on its own.

i used to get pain and the gum swelled slightly between two teeth at the back only if i got meat stuck in between them though, i had to dig the meat out it annoyed me and took a day for the swelling to go down, you could swish some salt water around see if that flushes anything out.

This sounds like just popcorn stuck in the gum. Even a tiny little bit can get stuck in there and cause things to get pretty irritated and inflamed.

I had something (a popcorn kernel or a skin of a bean) that got stuck in my gum behind my molar, and it irritated me for weeks. Flossing and brushing didn't help-- eventually it popped out one night while brushing, a long with a little blood, and the relief was instant.

I don't think there's anything really to worry about, especially since you know it started while eating popcorn. Brush and floss gently to keep things clean, and eventually the mechanical motion of eating and brushing will knock out whatever's bugging your gums. As far as I know, there's no long-term risk, it's just irritating.

(completely amateur opinion, take it for what it's worth. )