How Do I Accept My Body When People Make Fun Of Me?

Didn’t think I’d end up here but here I am. I have seeked everywhere for help that works for me but just can’t find any. I feel as if my body is holding me back. Let me explain, I’m 13 and always get told I gained weight at a gathering, get ridiculed when I eat one unhealthy thing in moderation and just feel bad about my looks. I hate my body, I hate looking in the mirror, I hate going to a body of water and I hate clothes. I feel ashamed to eat something unhealthy or take some food I’ve been offered because I don’t want to seem hungry all the time. I always hate being in my body because everybody keeps telling me if I was skinnier I would look way better. I hate that I try so hard to lose weight but my brother is skinny and constantly eats unhealthy but nobody cares because he can’t be unhealthy and skinny to them. I feel like I’ll never be good enough. I get called a “fatso” by my brother and cousins and it’s not like I can distance myself from my brother, especially in quarantine. I also got really upset when I realized my clothes got smaller on me and I knew they were small I just didn’t tell anybody because they would get mad at me for gaining weight. So instead I squeezed into those clothes and my body shape was showing which made me more upset I usually wear clothes more big on me to hide my body. I got told after eating popcorn once in an entire 3 months of not eating it that my eating is unhealthy. This made me really sad and I started crying for a while. It made me sad because I felt like everybody cared when I enjoyed a snack I barely eat and try to enjoy but when my brother does it many times nobody cares. I ended up throwing out the popcorn because of how guilty I felt. I’ve always felt like that before but just ignored it until now I’m sick of it. Everybody says eat healthy when my mom cooks rice with something else almost everyday and we don’t have the ingredients for all these other fancy meals that are healthy. Plus my mom never steps out of her comfort zone in cooking she will not make a recipe online. Sometimes we eat out, I try to eat at home but we don’t really have anything healthy other then fruits and vegetables nobody’s trying to eat that for dinner. I am very grateful for everything I have and my mom already raises 4 children one with a disability life is hard enough as it is for her and I don’t want her to have to make 2 meals one for me and the other for my siblings. I have tried dieting but it isn’t working for me I always get discouraged or very very hungry for something and end up eating a lot more. I don’t know how to lose weight and I don’t know how to feel better about my self the clothes not fitting me anymore makes me so sad that I can’t even control my weight gain. And I constantly get picked on I hate it I wish I could end it all but I would never try because my life means too much to me. I can’t help it anymore I feel like I’m losing my mind because no matter what I do I can never be happy with myself. My mom encourages me to be more healthier by biking and trying to guide me but even after my 40 min bike ride I take everyday I see no progress. I feel trapped inside my body literally! I feel like I can’t look good and be fat. I know being fat isn’t a good thing but I just don’t know how to lose it and nobody is helping to guide me and I can’t talk to a doctor about this because of COVID and just how awkward it will be too. Whenever I’m at the beach I always get stares by other people so now I wear a tank top every time. I love my little cousins she’s the sweetest I made a joke about my fat so other people wouldn’t and she took me aside and said no don’t say that! She said don’t feel like you are so fat and that u are not pretty. Pretty wise words from a 8 year old. She’s right but I still can’t get myself to think that and I want a change just don’t know where to start and how to keep it. I need guidance please.