were my friends ever my friends at all?

I can't believe all this shit is happening to me. my entire friend group is against me for something someone made up about me. my ex is in my friend group and basically she started targeting me this morning and i was kinda sad and also confused cuz yesterday she bought me a pizza, a soda, and even some gum. so she had me really confused when she treated me like this. she said things like "fatass" and she said that she did NOT want me to sit next to her. she told me that i was immature and ugly. she made fun of me and called me names but always ended her sentence with "no need to be mean but yeah" so i retaliated against her and she got all mad at me and told our friend group abt it. now our friend group believes her twisted words and explanation of what happened. i tried to explain but they just shut me up. even my best friend kai. didn't want me around. they said I'm out of the friend group. i told them they couldn't kick me out if i hadn't done anything wrong. but now I'm wondering if i should actually leave. ive been in this group since september. and i am having a hard time choosing. my ex even made a remark abt me having feelings for someone online and said it was dumb.