No, teacher, I'm saying the problem is that you're an asshole.
And, as a result, your class is full of assholes, so yes, it technically is a problem with how you handle your class, but first and foremost it's a problem with you.
"She looks poorer than the other kids, so they pick on her. That means it's her fault." What sort of bullshit brain came up with that conclusion? I suggest you turn it in for a refund.