Story time about my toxic friend

(Story time X3) I stopped talking with my toxic friend, and now shes trying to ruin my life. 

What she did: Me and my toxic friend, we'll call her L, have been friends for 8 years, maybe 9. My mom always knew there was something wrong with her but i was too much of a doormat to listen. Recently L has been acting like a bitch, calling me fat multiple times, knowing im insecure! not letting me have opinions, bringing me down so she can be on top. L loves humiliating me, but this time, she went too far. 

In front of the whole class, L talked about sending pics to a 20 year old on snap, when he saved the pics in the chat she got mad, so like any reasonable friend would, i told her "Stop sending him pictures then, if you dont want him to save them in chat". 

She. went. CRAZY. 

Calling me a pedophile supporter and "On the same team as rapists". i was only trying to protect her. Now shes taking all my friends from me, trying to make me jealous by saying "Oh me and (other friend, not me) are such good friends!! we love each otherrr" (actual words). Even a classmates noticed, and they try to cheer me up which is really sweet. but it doesnt make up for what L did. Shes spreading rumours about me so now no one wants to be my friend, and i know shes talking shit about me. Why? because i had to work with her and another girl, when the other girl opened L's snap, L became defensive and said "Dont open my snaps, people are around". normally shes never like that, and i was the only one around anyways. I really hate her, and i want revenge but my mom says i have to wait for karma. and this isnt just HALF of what shes done. 

Opinions?