Loose teeth in the middle School hallway

"I was standing in the middle of my old middle school hallway trying to hand someone a train ticket, but I kept getting distracted by this weird, dull ache along my jaw. I reached up and touched my front tooth, and it instantly felt completely loose, wiggling back and forth like a loose fence post. A horrible panic hit me, and I ran into a crowded bathroom to look in the mirror. When I opened my mouth, my teeth were soft, almost like wet chalk, and three of them just fell out right into my hand, making this tiny clicking sound. I was desperately trying to push them back into my gums before anyone noticed, but more kept slipping out, filling my mouth with this heavy, metallic taste. Then suddenly I was standing on a windy bridge in the rain, spitting out small handfuls of white gravel into the river below, feeling this total sickening dread that my whole mouth was just completely dissolving and I couldn't stop it."