I'm going to yell at my mum on the street
Why do you need to yell at your mom?
She is a mentally out of shape lady she can't take care of herself well. It frustrates me so much and I just want to scream.
I understand that dealing with her mental problems can be really frustrating but that doesn't mean you should yell at her in public for it.
I don't care what you say. I'm gonna yell at her and drive her nuts.
Purposely making a scene in front of strangers is pretty awful action to take just because it amuses you. Your mother may be very embarrassed already about her mental behavior and making it worse will only break her down more. Be the bigger person and ignore the situation.