I think you need to starting doing things that will improve your self esteem. You should force yourself into situations were you are uncomfortable and you may stutter. You should also be doing things to help your self esteem in other parts of your life. For example, you should start lifting weights (if you don't already). This will help in your overall confidence. You should find something you like and become good at it. This can be a hobby, sport, school, etc. Knowing that you are good at something will do wonders for your self esteem. Also, the most important thing is to really focus on not caring what others think about you. Just focus on what you want and go for it. You need tunnel vision.