Hey, coming from a 36-nearly A (can't even fit in A's), I just want to tell you that I know how you feel, as I used to feel the same way. I was teased, embarassed, etc.
But now, I am 41, and I am glad that I am small. My husband is fine with it. I have had 2 kids and breastfed both. When I was "more endowed" (thanks to milk) I realized how much breasts can get in the way, so I guess now I am thankful. And, they still don't sag! Hopefully you will come to accept their size. (Now, let's not talk about other body issues, I have a ton!)
Take care and HUGS!