Did I miss

 Any 

And you bitch

 Want to beat on this kitchen wall 

Psycho

 Above my head stomping all gotdam day 

Psycho maniac bitch

 On the other side of the wall in another apartment beating on the wall 

Really foul

 Really fucked up you are 

Making they

 Presence known 

Knowing it's a bitch

 Waiting for me to use the bathroom or take a bath 

It's bad enough

 To struggle with my issues  

How did you become

 A psycho  maniac bitch behind a bathroom mirror wall harassing me every time I use the bathroom 

Subjective to change