Not the first lady to complain of harassment here unfortunately, as for impersonating, amethyst on android has served me well, there is an icon on the people I follow and when people in my network report others then don't even appear in my feed.
Discussion
It can get ugly online and when it does I just step away but I will say that centralized platforms have amazing tools to navigate your experience. Nostr will be a harder sell for some folks that want a curated experience.