How Can I help my friends get along?

Okay. So my best friends are Livy,Mandy, and Mackenzie. But, Mackenzie and Mandy hate Livy So Livy hates them, And Mackenzie and I actually got into an actual FIGHT Fight about it Friday. I'm talkin blood here.now i'm suspended. ANd I'm so very confused because Livy is so awesome! She's funny and pretty and so very bubbly. And she's always got my back. For example, If we're walkin down the street and someone hit me and I got in a fight, She'd have my back like that. And Mandy Is Super sweet man I love her to death! Kenzie is just awesome to be friends with. usually. she leaves me hangin sometimes though. don't always have my back like Liv. But she's still a really good friend. I love them all 2 death, but they're thinking about each other's deaths. Advice? Anyone? please? Help? Me?