Ohh I see. Damn, must've really hurt!
Damn o.O I didn't really move into a C until maybe 11th grade. I wore a 36/38DD until a couple years ago when I learned to follow the more uniform UK sizing, which puts me in a 32GG. They aren't as big as yours, at least going by your tumblr picture, but to be honest my weight fluctuation has kind of ruined them and I've gotten a little pendulous. Makes things complicated -.- I've never had any back trouble.