Defense Against The Dark Arts 11: Abuse...
Abuse is not your fault.
Its people who are being Rude, because they themselves are in Pain...
They Project their Pain upon You, seeing You as the cause of them being hurt.
What can you do?
Realise these people are in pain and:
ITS NOT your job to Fix them.
Try to work to get them to think about what they do; once or twice.
when this fails after 3 times,, stop trying.
Then work to Leave for good.