Confidence is not about having the best looks or having the most perfect teeth and smoothest skin. Confidence is all about appreciating who you are, what you are, what you can do and most of all being proud of your ugliness.
Gorgeous women and handsome guys are the most insecure people in the world. Look at them... they always look for a doctor to do something with their face or body because despite of having good looks... they still feel incomplete, they still feel that there is something wrong in their body or face. And after one operation, they will schedule another operation next month. They never get tired of fixing their face. Some people gets even uglier because of too much operation.
Accept all the ugly parts in your body and face and you're already free. If you are really confident then you will never hide anything, you will be proud of it. If you can't be proud then just ignore it. Own your face, own your body, show it to the world. Never care if some people criticizes you.
Some people can look really great on stage despite of having fat bellies or imperfect teeth, those are the type of people who doesn't care of how they look. Striving to become beautiful is good, there is nothing wrong with it but if you really want to be happy then never fix anything with your appearance. You can change it naturally by doing some natural techniques to make your face and body beautiful but don't ever trust doctors because doing that means you don't have any confidence in your personality at all.
Try going out without makeup, try showing your skin without using any hiding device to hide your scars or ugly marks. Be proud of your ugliness, it is the best way to feel really confident. People will admire you, people will become impressed with you if you look very natural.