Weight problems-- intro

Soooo.... I'm 13 years old, 5'8, and 134 pounds. I'm not overweight, but I want to be 120. I used to starve myself and exercise every day for at least 30 minutes. I wasn't happy at all and I would see all of the other girls at lunch getting fries and chicken tenders, while I would get a salad. They were all so skinny, but they would eat whatever they want. After awhile, I stopped starving myself and execising every day. I did that because I was sad all the time and I wanted it to stop. I started eating more and more. I exercised 3 times a week. Sounds good, right? There's a whole story to this. Summer came and I stopped exercising because my dad is alwyas watching me. I feel like if I exercise in front of him he will judge me. I've talked to him about my problem with my weight and how I'm not happy with it and he told me to stop bothering him. I want to lose these few pounds the right way and not fall back into starving myself. I have a journal and I wrote on July 12, 2016 STARVATION OPERATION. That was when it first started. It continued from there. I just want some support. Ya know? I'm young and some people will judge me for wanting to lose some weight bc it's not extremely necessary. I wish I had an exercise buddy irl to go running with. I want to overcome this fear of being judged for exercising. I always did ecercise in secret. I don't want to do that anymore. Same thing with eating. I ate a sonic burger today because I felt like if I said no, my family would think I'm obsessing. They're food pushers. I don't understand why they call me fat, but then judge me for TRYING to be healthy. It's always been a problem. They comment on my big thighs and hips. It makes me super sad. I have no one. I'm trying so very hard not to just starve myself. How can I get my dad to help me? He always buy junk food even when I tell him not to. It makes it harder for me but he just doesn't care. I have to have even more self control. Bottom line is I want to lose weight but I don't want to be judged and I want to do it the right way. I would love to hear some advice.