@daallday what are
you on about?
One wouldn't assume it's just some "fanfiction" once you notice how accurate it was, it could be some diary about you written by someone in your home, most likely your parents or another family member. And that's only until you realize how it's accurate on everything that no one else but you could've known like your exact thoughts emotions and every actions.
Another likely theory would then be it's some magical book of prophecy or a diary from the future or whatever, especially when it's starts talking about the future and given how accurate it has been so far.
Fanfiction is the last thing anyone would assume. Even if you think it's fan fiction, you'd still want to find out what kind of story and future it is especially when it concerns you.