All women's breasts fluctuate when they lose or gain weight.
It sucks, right?
You wish you could just take some fat from your thighs or ass and stick it up in your boobies. Wouldn't that be cool?
It's like a trade off.. be fit and trim with smaller boobs, or soft and curvy with bigger boobs. I have the same dilemma as you, so I'm trying to stay somewhere in the middle..