How to handle a big fight with best friend from class?

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I started high school last year, and since the beginning of october when we first talked more than usually, we became closer and closer until we were literally every day, all day together in school..and for the last two months, we've had smaller disagreements, until it became really bad and we started hurting each other unconsciously and people became against our friendship, and on Saturday night she told me we should separate until things calm down a little..she told me it's for my own good, and she said she misses me ''more than i miss her'', but it's still a real struggle for me..i'm alone most of the time in school, until she's always with these 3 girls that i'm in a great relationship with, but i just can't go and hang out with them because it kills me when i'm near her..and she deleted me on fb today. I know i sound pathetic a lot, but we've been unseparatable for 6 months and now we don't even look at each other, i don't know how to deal with it easily..we literally sit next to each other on most classes..
We tried talking yesterday but it just got worse, so we definitively realized that things can't get better now and we're definitively separating for some time..I've asked how to go through it easier, not how to fix our relationship..i wish it was easy at this point :/