You know, the same thing happened to me in high school.
My best friend left me because I wasn't cool enough. All my other friends moved away within 6 months and because we were the only 2 left, she left me, found a bunch of other people and bad-mouthed me to everyone so that she could fit in.
If Emily and Chloe do end up leaving with your other friend, then obviously they weren't good friends to begin with. Continue to be nice to them, but at the same time, start being friendly with other people so that if you do end up being alone, you can easily just make new friends because you were already friendly with those people.
Your other two friends (Emily and Chloe) are probably acting different because they're caught in the middle or maybe, you're just worried things are different.
Habe you and this Keely girl ever gotten the chance to talk alone? Maybe, make plans to meet somewhere for coffee or something and just talk, listen to her and then you spill your guts out.
My best friend left me because I wasn't cool enough. All my other friends moved away within 6 months and because we were the only 2 left, she left me, found a bunch of other people and bad-mouthed me to everyone so that she could fit in.
If Emily and Chloe do end up leaving with your other friend, then obviously they weren't good friends to begin with. Continue to be nice to them, but at the same time, start being friendly with other people so that if you do end up being alone, you can easily just make new friends because you were already friendly with those people.