Eating Disorder Due To Bullying

it started in first year, when i was 11, i had been bullied previously in primary school but always had Friends and other interests to keep me occupied, i was at an all girls independent school and the classes were small and so were the groups of Friends we had. one day they decided to leave me out of their groups, i wasn't picked to be partners or in sports teams or invited to parties, they would talk about me behind my back for no apparent reason, i wasn't different to the others, they just decided to victimize me. i became obsessed they were talking about me all the time and spreading rumors, running away from me at break times, i was so paranoid, and i assumed it was because of the way i looked. i became depressed and pulled out of school sports teams, causing me to gain weight as i was still eating the same. after moving schools, i had new Friends and my life was going fine, and i could deal with the bully's as long as i had Friends. then one day they as well started to leave me out, talk behind me back and anything they said; (a compliment or something they liked) was in sarcasm and intended to mock me. i was on edge the whole time, i be lived they were talking about me all the time, i started to self harm, cutting tiny cuts in my arms and hands. i started to eat more out of depression and people started to notice i was gaining weight, and started calling me fat. after that i became very self conscious and didn't want to go out of the house in case i saw people i knew who would laugh at me for being fat and bullied. so i stopped eating around others, i wouldn't eat anything at school , but then come home and binge on foods like pasta, crisps, chocolate, cheese any kind of comfort food, i was so down i regularly thought of ways to end my life, i skived school and planed on running away. then after 5 years we were studying for our gcse exams and got study leave, so i only had to come into school for my exams, when i didn't see anyone at school i became relaxed and started to eat healthily and exercising, dropping 2stone in 3 months, i was still fat , but more of an average fat, (UK size 14) i started a new school for sixth form was still loosing weight, i had Friends and nobody was talked behind my back, although i am still extremely paranoid about everything people say, i over Analise things hand have mild COD, but recently we have been having exam pressure, my friend who i was planning to go on holiday with dropped out, and i felt utter abandonment, I felt like i had been let down so much and i began to think nobody cared about me, which led to intense binging and purging, i would binge and feel so bad, i would'nt not eat anything , then binge again, eventually i put on 4 pounds a week,
and here i am, my social life is so turbulent, i have developed social anxiety, paranoia people are talking about me
and i cant stop eating, i don't know what to do :(