Procurando por um conto sobre um homem aprisionado em sua própria cabeça

Este é o The White Room de W. Kevin Christian.

The room was not cold. It was not wet. It was not noisy or colorful. It was quiet and white. No pictures on the walls. No carpet on the floors. There was just a table with a man on it and a black-and-white digital clock hung from the ceiling directly above his head. The clock read: 9,999 years, 364 days, 23 hours, 58 minutes, 11 seconds…12…13…

...

A perverse grin crossed the bald man’s face, his mouth letting out a slow, toad-like chuckle. The feeling of power intoxicated him. The look 30 seconds with the program could put on a person’s face! It tickled him in the darkest of ways, as if holding something young and innocent at the edge of a cliff overlooking hell. The power! The suffering!

Poderia ser " O Longo Sono " de Richard "Zig" Zagorski?

A premissa chave é que o protagonista está preso dentro de sua própria cabeça durante uma viagem de 200 anos.

For whatever reason, Gerald was not asleep and unaware in stasis – not completely anyway. The only sense that functioned was his hearing. He felt nothing against his skin, he saw nothing …he wasn’t even sure if his eyes were open. And with his nasal passages filled with stasis fluid, he smelled nothing at all. But he could hear the slushing of the stasis fluid being refreshed periodically, as it would do each passing hour of the 200-year voyage.