Friend problems?? How do I handle this?

Okay, so, i have this friend, lets call her Ari. And I recently decided not to be friends with her anymore. She was always making mean comments to me. And when she was being mean to my other friend, one of my best friends, I said something. I told her to stop being mean etc etc. When I said that, she said if you say that again, i'm going to tell, lets call him Ric(the guy i really, really like) that she'd tell him everything i have said and all the texts i've sent her about him. And so i decided not to be friends. She did a lot more but i don't want to write you a novel. And she's always hugging my best friend in front of me purposely because she knows i won't go up and say anything. But, ive beem looking on facebook about things that we've said, inside jokes etc.and i almost feel bad that i'm not friends with her anymore. so what do i do do keep myself from feeling bad sometimes? And she knows too much about me, what do i do if she starts to threaten me again? Thanks in advance!!!