Im being stalked on insta

Gee

So for context i sell underwear but its very much anonymous, (you wouldn’t find me unless you knew my name) and yesterday i got a dm from an account that had just been made saying ‘hi are you down to sell your underwear’ and i freaked out because what i do is DISCREET so idk how this person found me, i just replied asking how they got my page. They didn’t respond and now they STILL follow only me and watch all my stories and im super uncomfortable. YES i will block them but i wanna know if theres anyway i can figure out who it could be?? I’ve already sent an email so i know its someone beginning with A but thats all. Any of you cis girlies know what else i can do? :)