Im so lost

So this is currently happening and i have no idea what to do. earlier on this year, i moved friendship groups from the nicest, most down to earth girls, to the bitchy, popular group. now i think about it, it was the worst decision, considering those same girls bullied me the year before. About 6 months ago, i moved groups and for the first month, it was great. the four girls were so nice to me, commented on my instagrams, hugged me when i came to school, was invited to a sleepover or two etc. then after a little while, one of the girls, who im going to call G, started ignoring me isolating me. after she started,another girl in the group called A started too. so for a while G and A were ignoring me and spreading rumours about me. the two other girls were still nice to me, L and O but i dont think they actually like me. i feel like they are only nice to me because i have no other friends. i came to this school last year and havnt really found a group yet. its kinda hard to just move to another group because there arent many girls in my year (im at an only girls school) and the popular group has about 30 girls in it, so once im out of one of the pop groups i cant join any other. (its not that i want to be popular, its just the other girls are the right kind of people.) back to the story, this girl G, is in a group with me for everything, including a drama production. im quite shy and not very good at standing up for myself to its hard to tell her to stop. she has assigned me as ‘tech support’ for a 4 person play and said that i can write the script and just do whatever. the last week, its gotten quite bad and i don’t know what to do. today at lunch, we were talking about our weight. she said ‘tbh our group is quite thick’ and L says yeah apart from H (me) and g says ‘sorry I said in the GROUP’ emphasising that I wasn’t apart of the group. this really hurt too bc everyone always teases me for being skinny and no one can know I have anorexia. I’m getting better and dealing with it, but having Ana doesn’t help to deal with all this. G has also blocked me on snap idk why and shes encouraging the other girls to as well. I was in a chat with them and g deleted it and made a new one called ‘the REAL group’ so that’s not great. there is so much more to say and its really hard to explain what’s going on. sorry if this is really messy I just need to say something. because no one knows what’s going on. its also really hard bc I live in boarding school and my roommate is terrible. she spreads rumours about me to G and twists and turns everything i say. she calls me ‘too skinny’ and too flat and to short and pale and my fashion sense is gross and i have a terrible boyfriend. another thing G and A do is tease me for my bf bc hes older and they say hes ugly and gay which he isnt and it really hurts because not many guys like me bc im so ugly so when a guy likes me it makes me feel better. G was also spreading rumours about me to my bf which sucked. the four of them always say things like ‘the four of us should have a sleepover this weekend’ when im standing right there. its not fun to be ignored and please please speak up if you are going through something like this becuase i cant.