Teenage is a phase...

Unfortunately as long as you hate yourself, nothing you do will ever prevent these fears you have. You could be beautiful, intelligent, and successful, none of that will matter as long as you hate yourself because you'll always see everything negatively anyways. My advice would be learn how to love yourself more by focusing on positives instead.

Personally I just lean on God. He makes everyone special in our own way. Knowing your strengths is also super important! Take personality assessments to learn your personality strengths. Also a therapist can help you realize your worth. A man will be attracted to you because of looks at first, but love you for being you! Don't change for anyone. I am doing the Atkins diet now to become healthier, its the only way for me to lose my apetite for sweets and carbs, it really works fast. I only eat protein for a few weeks and then slowly integrate other foods.
And count your blessings every day. SSRI meds can also help a lot, a regular doctor can prescribe them because they aren't addicting but really work good. But it takes 8 weeks for them to work so you have to be patient. I've taken them a couple times in the past and they helped me a lot during hard times.

I would do a course in cognitive behavior therapy. You learn to transform your negative thoughts into positive ones

How about transferring to a school more in line with your interests? Can u do that?

Also were u forced to do things against your will all your life?

I bet if you posted a pic, you'd hear differently.