By ghosting them. Doubt this will help you though, since it's the most obvious option and I'm sure you thought of it and there are reasons why it isn't possible.
The people who have erotomania at me *think* I'm responding secretly to them with my tweets and blog posts, so me actually not responding to them doesn't help. It's not a reasonable disorder.
Tim Ferriss mentioned this exact problem in his recent post: https://tim.blog/2020/02/02/reasons-to-not-become-famous/…. Low on precise details, but got the FBI involved and family got the guy back on his meds. Also recommends a lot of things you already do (use a pseudonym, don't let people know location, etc.)
It weren't reasonably people for me either. Circumstances made it easier for me than it seems for you.
The way you make it sound, the police may well be your only option.