I need advice, please.

I am Fifteen. I am in a lot of sports. The only time I have after school is when I clean, do dishes, eat, and possibly watch TV. But my brothers are home with me. A really good friend of mine at school made up a whole bunch of lies about me, saying I want to have threesomes with my cousin and my best friend, and that I sent nudes to her. But the account on Snapchat that she said I sent them from I don't own. She said she didn't see their face but could tell it was me. She gets nudes from random people she doesn't know all the time but blames me for it, and I freaked out because I thought my best friend was going to hate me because of what she was saying. I just want to know what I should do, because it hurts that she lied and is spreading rumors. I thought she was supposed to be my "friend".