Should I stay her friend or not? Please help!

My friend and one other girl chased me into a bathroom stall,by threatening to hit me with a metal water bottle,and locked me in there. They were recording me screaming for them to let me out with their phones. Then when a teacher heard me and came in the jumped away from the door to make it look like they weren’t doing anything. They didn’t put their phones away and the teacher confiscated them. They blamed me. My friend told me I’m a b***h. Then a few weeks later I said something and made her crack up. She told me she loved me and said she wanted me to be her best friend forever. I don’t know what to do, she’s really funny and can be nice but I’m not sure if I should stay friends with her or not. Help?