Being eternally trapped in a mental prison. Imagine having a panic attack that never ends. I'm pretty sure that type of prolonged stress would cause a psychotic break where your psyche fractures and you become a despondent shell. You would become deathly afraid of everything, even the people you love, because of an unceasing paranoia. That basically sounds like hell to me.
I'm not really afraid of the idea of nothingness after death, because at least then I am released from the torment of living.
Monster
74 episodes. Psychological thriller. Serial murder mystery, but instead of "whodunit?" it's "whydunit?". Dramatic as an opera. No weird tropes. Superb character development. I love Magnificent Steiner.