How can I reduce the size of my breasts?

My breasts are not proportional to my body at all. I'm 5'4", 120 lbs, and have 34 DD breasts. I'm 17 and my breast have been growing since I've been 8 years old. I just started taking birth control and I think the hormones made my breasts get slightly bigger now. It's extremely uncomfortable physically and especially emotionally, and I have no idea what to do. I heard cardio workouts can help you lose fat all over, including in the breasts, but I worry since I'm not overweight if it'd even work. I've heard of herbal pills that can reduce the size of your breasts, but that's probably just some more hormonal pills that might mess with something else on my body. I've really been considering breast reduction surgery when I turn 18 but I have awhile till then and I'd like to try some alternatives before then. I'm just really starting to feel hopeless, however, since they only keep getting bigger. Help me, please!