To me, beauty is about far far more than looks.
Happiness, confidence, being happy in one's own skin...so many things can contribute to a person's beauty.
Anorexia robs you of so much of this, I know from experience.
One of the best things you could ever give yourself is to work on your inner beauty, let yourself be happy and healthy, learn to love yourself.
I remember feeling as you did. The strange thing is, I look back at photos of me back in the bad days and listen to people say how much better I look now (believe me, I am certainly not thin anymore - my world did not collapse, I have a figure and curves and some peace from the demons and obsession and have so many other, far better things to fill my head with) and I'm actually at the point where I can see it myself.
Learn to let go of the obsession and control, fill it with other, better things which make you happy and which you drive, not the other way around. Freedom is a wonderful thing. It might not seem like it sometimes but you can take the control back.
It can take a lot of time and effort andcan be a long hard road but it is more than worth it and you can do it if you want to.