Painful pimple? on vagina

Bailie

So I barely ever wax and only shave like once every few months and occasionally use Nair down there but I haven't really touched it in a while cuz honestly it doesn't bother me and it's just too much work to put in for something that's gonna be back. So a few days ago I started to notice small bump and didn't think much into it but today it got a lot bigger and is super painful. At first I thought it was like and ingrown hair or infection but those usually happen after doing something to the hair I thought.... I'm kinda freaking out. This has never happened to me and it is extremely painful especially when I'm moving around and it rubs against my underwear. If anyone knows what this could be and how to get rid of it lmk please.