*Disclaimer: Wolfsnake is not a doctor. He does assist with surgeries on animals, though.*
I would be lying if I said I never considered doing this myself. But I know how incredibly unwise it would be. Let's just break it down:
First off, there's the pain issue. Let's just say that somehow, you manage to acquire some form of anesthetic that numbs your breast area without depressing your central nervous system and without causing cardiac suppression, respiratory depression, or worse. So you don't go into shock from the pain, and you can keep a clear head during surgery. Let's also pretend you've found some sterile instruments and materials to use, topical antiseptics, sterile surgical attire, and an incredibly clean dust-free operating room so you don't give yourself septicemia (a life-threatening systemic bloodborn infection, caused by improper surgical technique). Let's also say you know how to wash up for surgery and maintain sterility during the operation.
Your heart and lungs are reasonably well-protected by your ribs. However, breast tissue is highly vascular, meaning there are a ->-bleeped-<-load of veins and arteries going in and out of it. Without a three-dimensional understanding of the vascular pattern in that area, and without the ability to ligate (clamp or tie off) each major blood vessel individually, you could easily bleed enough to cause serious trouble or just plain death. This is not even considering the lymphatic system or all the nerves you could run into. Even if you had the ability to navigate this, by yourself, you would probably be unable to remove all the breast tissue (which goes all the way up to the armpits, from what I have read), properly graft the nipples, and suture up each layer of tissue correctly. You are very likely to end up with, at absolute minimum, infection, long-term nerve problems, and horribly disfiguring scars that could limit your mobility. At worst, you could literally kill yourself through blood loss or septicemia.
People who want to be surgeons go through, last I checked, up to 15 years of school and on-the-job training. That's 4 years undergrad, 4 years med school, and 7 years of residency/internship. And even they screw up. They also, in addition, usually have the assistance of at least three, but usually more, highly-trained assistants to monitor anesthesia, help with the operation, ligate, pass materials, monitor patient vital signs, etc., etc., etc.
So please, please, please...wait. Let someone who can give you a beautiful chest, safely, do it for you. I know it seems like a lot of money and too many years. But you will get there.
And in the meantime, exercise. Especially focus on back and chest muscles, and on maintaining good posture. This will help minimize body fat, and therefore minimize breast size.
