There's a really amazing story in the New Yorker about how Albert Woodfox survived solitary confinement:
"Woodfox often woke up gasping. He felt that the walls of the cell were squeezing him to death, a sensation that he began to experience the day after his mother’s funeral, in 1994. He had planned to go to the burial—prisoners at Angola are permitted to attend the funerals of immediate family—but at the last minute his request was denied. For three years, he slept sitting up, because he felt less panicked when he was vertical. 'It takes so much out of you just to try to make these walls, you know, go back to the normal place they belong,' he told a psychologist. 'Someday I’m not going to be able to deal with it. I’m not going to be able to pull those walls apart.'" --
Relatedly, if you haven't read Shane Bauer's expose of life as a prison guard, do.