How do you get rid of a psycho friend who's making me depressed?

Ahhh, I know a person exactly like that, but worse, believe me... the way I got out of it was at the end of the year, she found out something bad has happened and somehow thinks it is my fault... so she starts bullying me... and I told her how much I really hate her and she tells her mom, who makes a big deal over it and starts yelling at me... you see, her mom has this rule that goes "like my daughter, or die." and so I gave her parenting advice and now she hates me forever but now someone 2 years older than me says I am her personal hero now, because I told those 2 off and I did it without even raising my voice... so yeah, that's how I got rid of her. And yes, I did go through a LOT of emotional stress and depression with that girl... thing is, more than likely, I will meet another girl like her in no time. she is leaving school and won't be coming next year thank God... she thought everyone loved her but actually everyone hates her, they are just afraid of her mom so they never tell her.I sympathize foryou