Am I leading to an eating disorder ?

[sookala123]

I'm 5'4 , 16 years old , female and 129 pounds . I used to love eating , but then had a massive change in my life and I wanted to lose weight fast . So I did the IU diet for a week and worked out every night . A month later I began counting calories and that lasted for 2 months . Now I feel guilty about eating everything . I've made myself vomit 3 times and I have stopped going to party's and gatherings because I think I look too big and ugly . I used to weigh everything I ate but now I already know my portion sizes  . Now I eat an average of 1250 calories a day , but constantly switch from a starvation mindset ( to eat as little as possible for a day or two ) , to eating 1250 cals . I can barely look at myself in the mirror anymore . I measure my waist in inches every night ( at the moment 29" ) . I also have an under active thyroid and Addison's Disease . I fear eating out with my friends incase I eat too much and I never finish my plate . I bring as little as food possible to school , like only eating 1 apple from 7 am to 4:30 pm and nothing else . I always want to be the healthiest , the one who eats the least amount in my group and fear eating alone incase I can't control myself . I used to enjoy eating but now I fear it and I fear gaining any weight . I constantly have migraines and feel frustrated . I also have been feeling very isolated lately .  I don't know whether I'm on the verge of an eating disorder , already have one , or I am just over exaggerating . I don't want to tell any of my friends incase I scare them away or they take me as a joke , so can someone please help me on what I should do because I'm so confused and too scared to ask for help  .