Crumbling molar and the unnoticed Panic

"I was just chewing on a piece of bread, nothing weird, until my teeth hit something sharp. There was this loud tiny crack, and half my lower molar just crumbled apart in my mouth. No blood at first, just all these sharp little shards rolling around under my tongue. I tried to spit them into a napkin, but more bits kept breaking off, like the whole tooth was turning into dry biscuit crumbs. I patted my pockets for my phone to call the dentist, but all I pulled out were old grocery receipts. The friend I was eating with just kept talking about their weekend hike, didn't even notice I was spitting broken tooth pieces into a plate. I pressed my tongue to the gap, and the rest of the tooth just dissolved. That's when the cold panic hit. I couldn't close my mouth right, kept thinking I'd swallow a sharp shard and choke. Then I jolted awake, hand flying to my jaw, and bit down gently a few times. The tooth was still there, solid, no cracks. My heart was still hammering for ages after, like I'd actually broken it for real."