I had a breast reduction when I was 15 (about a week before my birthday). I can say, without a doubt, it was the best thing that I have done.
I was about a 10G (but I was probably a 8H but they didn't make them). I had had large breasts ever since I got into puberty. I was a 10DD by the time I was 12. I did a lot of dancing (3 days a week) and it was excruciatingly painful, my back was stuffed and I had to get a bra custom made.
I got a referral from my GP and had it done at Cabrini Hospital in Malven with Simon Laurie. He was FANTASTIC. Professional, reassuring and great bedside manner. It took me about 6 weeks to get back to full 100%. I had a cut around the nipple and down. I didn't cut undeneath in the breast and the nipple was not cut off. I have regained 100% sensitivity in one nipple and about 95% in the other.
Nearly 8-9 years on and scarring is virtually unnoticable. I went to a 10D and now with getting a bit older and weight gain, I am a 10DD again.
My advice to you is to see a couple of plastic surgeons and find one you are comfortable with. THe first one I saw only reccomended breast liposuction, but this was a bit of a joke as it would have only taken me down a cup size (as my boobs were all boobs and not fat).
Another friend of mine from dancing had her done (she was about a 8FF) and my cousin, and a friend from work. I can say with total honesty that it was the best thing we have all done (had long conversations about it!).
Good luck and if you need some more info feel free to ask