Punk, I was 5'6" at your age and nice boobs, 34B; even if you change things, they won't "stay" how you change them. I also weighed 127 and was pretty good looking but didn't "find" the right husband until I was 35 and 160-170 pounds. When I got married at 39, I had just lost 18 pounds to weigh 180. Now I'm 56, still married, 5'5-1/2" (at best :-) and weigh 260 with the big boobs I wanted at your age only I don't want them anymore (46D). None of that has anything at all to do with my problems/self esteem or how/why I found a good husband and love life now!

You can't do better than "God" at designing you, you can only do better at appreciating you. There are no "mistakes" in our looks or who we "are", we just have the "job" of figuring out what we've got and how best to use it. We're a package deal, don't rip the wrapping paper?