Eating disorder

Women are designed by nature to be fat. There is a single woman without fat on her bones in the world, but she has an unique medical condition - her metabolism has speed of light and she had to eat all day just to survive, and she looks like she is 70-80 years old even she is 20-30 old at moment when that video was made.
These bastards who replaces "healthy" with BMI or simply unrea weight numbers, is not best thing to follow.
First. just "wash" your head and split your feels, wishes and desires, and the feels, wises and desires promoted by the media and so called "beauty industry".
This is a single way to rescue. If you ever live to live, of course.

You are beautiful and glorious just as you are. Stop thinking anything is perfect or what your definition of perfect is..it's subjective and always changing. You will just end up making yourself crazy and obsessive and just plain unhealthy. Everyone has squishy parts that they don't like or cellulite. Learn to look in the mirror and not only accept the way you look, but LOVE the way you look and how who you are. It's not easy because as humans we struggle with acceptance (especially our own) everyday. But do things to make you feel good about yourself..and those things include taking care of yourself. You are still so young and developing and your body needs food to fuel your body and mind. Learn about nutrition. But don't go crazy and not ever allow some foods. Learn moderation. Drink plenty of water, get enough sleep, eat veggies, EXERCISE!! (Yoga - like the comment below suggested) Limit junk foods (sugar, soda, candy etc). But if you have an eating disorder you may not be able to just stop it on your own. Eating disorders are diseases..and you may need the help of a therapist to help you. Most importantly be kind to yourself.

Start doing yoga

U shud love your body for u no matter what you look like or what people say