Why can't I read fanfiction??

Ok, this is a weird question you probably weren't expecting to find, but I genuinely don't get it.

I have several Rainworld fanfictions that I want to read, and I write a ton of my own without any difficulty, but I just... lose my goddamn mind when I try to read one. About one chapter in, I start fangirling way too hard over the concept, and I panic and quit reading it.

I genuinely don't know if it's because of my Autistic hyperfixation on Rainworld or if this is a normal experience when reading fanfictions in any fandom. Does anyone else experience this?? Asking specifically the Rainworld fandom because I feel like a lot of us act similarly due to our interest in the game.