When I was ten, I had 36C breasts and I was overweight (10 stone!). A month later, when I started puberty I lost loads of weight but it didn't solve the boob 'problem'. Now, if you have already started, all you can do is take regular exercise and eat healthily. It may reduce your bra size or not.
I would recommend a bra common in most shops, a minimizing bra.
They come in many shapes and styles, colours (note: english term) and more. They minimize your bust so they look smaller. You should be proud of them. I was teased as well, and I hated clothes shopping. Nothing nice would fit.
Breast reduction is not needed. Most men think they are quite nice, really. I was in your position, at 13, but I was already a D and not really bothered. They did not grow any more and I have stayed a D.
From experience, you dont need it. Ive done a few breast reductions on ladies who want smaller ones, and I've managed to persuade D cup women to not have it done.
Eat healthily, take more excersise, and you could do with losing a bit of weight. I could help. Personally, I wouldn''t do anything but if you are really bothered about them, a minimising bra works wonders.
Also, with every boyfriend you get, make sure they want you, not your boobs. If they really care about you, they don't care about them and you'll know if you've found the right guy. Your friend may not want yours, but their not hers and she will be really jealous of you in a few years time. She wont have any breasts, and you'll have perfect breasts.
I suffered the same thing.
Hope I helped
I am a trainee doctor in London, England