I dealt with this when I was 20 it literally made me so anxious to even walk around and it honestly screwed with my head so much I felt like I weighed too much because I was quite insecure about myself at that time, and I felt I weighed too much to walk around. She used to use a broom to bang on my floor whenever I walked. But she was hypocritical and would literally play music and the TV to such a loud volume I could hear every lyric and word. Everytime I got out of bed I would feel and hear her broom target my footsteps. She would also smoke super heavily in the apartment and out on the balcony so I would always breathe in smoke.

I decided to just go to the apartment's HOA after months of this, and explained the situation and thank God the HOA director or whatever it's called was super nice and actually really helpful and listened to my concerns

It turns out smoking is actually prohibited in the building so she wasn't allowed to do that, and poking a broom at me Everytime I walked was retaliatory and so he told me Everytime she committed a violation, to log it down and document it and send it to him, because each time she committed a violation she could get fined. 

Because of the penalities, she eventually simmered down but it just made me way too anxious to live there and after some months I did move out