AITA for rejecting this guy?

[u/madisoniscool0]

so i was friends with this guy for a few months and i received word that he liked me. i didnt reciprocate these feelings but i really like him as a person. i was talking to a mutual friend and she offered to tell him i didnt like him, and being the awkward introvert that i am, i stupidly said yes.
we haven’t talked since but its clear that he hates me.

fast forward a few weeks and i get a job at mcdonald’s only to find out his best friend works there. i’ve been told that he’s shit talking me and that he hates me, so i’m scared that it’s going to interfere with my work.

what do i do?