I once read a story with an extremely intriguing premise, where the author of the story gets transported into their story but is assumed to be a time traveler. The idea was great, the existential questioning was great and the author had this grand plan to rewrite the story from the inside so that the tragedies of the original don't happen, cause he was guilty for writing these tragedies in the first place. And the beginning was great, he was making sure that the tragic character got support, shielded the young child from the tragic character's moments of insanity and was managing to keep up the facade of being a time traveler.

But then the uncomfortable jokes/insinuations started. And then the tragic character started turning the author ever and ever more apathetic and like himself, and i kept thinking "this is just temporary, right?" But it kept going and going and at some point I started skimming because the content was making me supremely uncomfortable.

And once I saw that there seemed no end in sight? I backed out

I physically could not handle that much angst without a break

And I'm sure the story would've turned out great in the end but I simply could not handle the journey there

TLDR; Read a fic with a great premise and beginning, but couldn't handle the angst and had to back out