You eventually hit Planck length The magical size bracelet chapter 32 by SatireMarker

You kept shrinking and shrinking until atoms became galaxies. You knew, from your research into size, that you must soon be coming up on the Planck length, the smallest known distance. You would become a quantum object, and who knew what that might mean. It might become impossible for Josh to grow you back; you were terrified.

You shrank further and further until light blue quantum foam became visible, spacetime itself now visible to you. It was a raging sea that soon surrounded you as you shrank into it; you weren't drowning in it as it didn't have the properties of water. Rather, it oppressed you, closing in on your face, blinding you to everything. You couldn't conceive of what was happening as you were borne about by spacetime itself.

Suddenly you felt an incredible pull of gravity as you saw a miniscule black hole opened up. Though you tried to resist, your rapidly shrinking body was pulled through it almost immediately, the vicious pull of the gravity yanking you through. The pull of it briefly stopped, but you were still surrounded by the quantum foam so you had no idea what had even happened. Then you were pulled into another, then another.

After this happened a few dozen times, helplessly pulled between ever-expanding miniscule black holes, your mind almost broke and you lost consciousness.

You came to your senses to find yourself still lost in the quantum foam, shrinking ever smaller, when suddenly you stopped shrinking entirely; you could feel it. What has happened?