My friend, the fiction didn’t harm you.

Your mental illness harmed you.

Random writers on the internet are not responsible for managing your mental illness for you.

You are responsible for managing your mental illness.

I knew while reading that it was affecting me in some way, but I kept reading because well, I’m mentally ill

This is self harm. You were engaging in self-harming behavior by continuing to read a fanfiction that you knew was triggering to you.

👉 You are responsible for managing your mental illness.

👉 Writers are not responsible for managing your mental illness for you.

And I hate to tell you this but messaging the author about it was absolutely harassing the author.