Refer people to your npub if they are unsure on if it's you or not. No one cab fake your npub, that's your identity.

Congratulations? That’s rare for a profile with so few followers. (I don’t mean that in a condescending way.)

You can't do much of anything with any real affect. Anyone can do whatever they want here.

There are a few things you can do to fight impersonation. You can flag the user for “spam” or “other” or something. Some apps will then show a warning on their profile. You can also link your nostr profile to your website if you have one. This is a bit technical (search NIP-05) but it cryptographically proved that you own both the website and your nostr account.

Most apps also have some kind of web-of-trust features to help. For example Nos sorts people by the number of people you both know, so if I search for Slice Design in Nos you show up at the top because more of my friends follow you than the imposter.

Is the impersonating account nostr:npub12ch8v58lkj7ffz3rpa39xcxplhdyjn5f5jynfnrju3e9h6vn27qs7jn6lh ? Because that account is actually bridged over from Mastodon. Somebody is mirroring a lot of accounts from there to Nostr.