I used to be cool but then I lost my friends and now I'm not?

[705]

Up until a couple of months ago I had a ton of friends, guys liked me, and I went to parties. I was part of this group of about 5 other girls and I was kinda the leader of the group, but suddenly one day they all turned on me and decided they hated me. One of the girls said they should kick me out of the group, but I thought that would never happen because I stayed friends with all the other girls except that one after the fight. But recently, I have no idea why, all of them, including my best friend, decided to ditch me. The group always hangs out without me and then shoves it in my face with instagram and snapchat. When the girls see me in the hallway, they ignore me. It hurts so bad and I have no idea what I did. Plus, the majority of the new friends I made this year now apparently think I'm a loser too and no one will talk to me. I have no idea what happened. I used to be part of the cool crowd and now I'm alone a lot and no one likes me anymore. Guys don't talk to me like they used to, I ALWAYS have to text people first to hang out and even they generally say they "can't", and I hardly get any likes on my facebook or instagram pictures (I used to get a lot). I feel like such a loser and I have no idea why they ditched me so easily, especially because they were my best friends. What can I do? I'm sick of feeling like this and having everyone now hate me.