Who else is a dancer that wants to achieve serious goals!!??

I didn't do ballet, but I did do jazz and stage dance. And this probably really isn't what you want to hear, but here goes.
My experience? The damage that I did to my body in my teens and twenties trying to get to the 'ideal weight and strength' was not worth it. I'm in my 40s now and have damaged knees, ankles, hips and spine. I have ulcers that stem directly from the severe dieting to reach the 'perfect ideal weight' which I now realize is about twenty pounds under 'healthy' for my size and body type. I was in the studio five to six hours a day, in the gym at least two, seven days a week. Looking back, it's really easy to see that I was a neurotic messed up woman-child trying to work towards an impossible ideal. By 23, it was clear that I would never be a lead, and that my body was already too broken to continue trying.

Like i said, probably NOT the answer you were looking for, but every time I see that "ideal weight and strength" for dancers, I cringe. Dance is beautiful, and my heart still soars when I see a dance move executed well, (and, yes, I'm envious!) but there is a cost that is paid for that perfection. Be sure you're prepared to pay it.