Having some problems at school with friends?

So me and this friend (her name will be Jen), we had fallen out this week. She was ignoring me and we were on our way to assembly and I stopped walking and realized she carried on walking and chatting without me. So then I thought I shouldn't waste my time with her if shes going to ignore me. So me and my other two friends (I'll name them Georgia and Ruby), we hung out without Jen and her little bum chums. After school I find out that Jen and Esther (Jens friend) were bitching about me on facebook, Jen said to Esther that she wouldn't hang out with Ruby and me after summer,so I was really angry and I thought why do I want to be friends with her? So the next day at School Jen and her bum bums were trying to make me jealous by hanging out with loads of people but in our form most people don't like Jen. So the week went on with me and Georgia and Ruby hanging out but I missed Jen because we were really good friends on so facebook I asked her if she wanted to be friends again and she kept avoiding the question so I put her on the spot and asked her and she said she has to think about it (but I already knew the answer.) and on fb I put my status as 'Some people are sad and pathetic making boyfriends up' and some people liked my status so Jen and Esther kept commenting on it with mean stuff to me... It was Jen who was making up fake boyfriends to make me jealous. So I deleted her on fb. and now I dunno what to do;/ i'm so confused and unhappy at school at the moment. What should I do?