I have been stuttering since when I was about 2 years old. I know what you feel. The engine of my whole life has always been "I have to demonstrate I am better than others". At school, in writted exams I was the best. At age of 16 I was the best in math over the whole school. At secondary school I was the only one to get 60/60 at final exam among about 100 pupils (in that period in Italy the base for score was over 60). I then studied industrial engineering in 5 years. I have done many many other things. I did speech training. Not "training for stutterers to speak cottectly", listen to me, I did "training for normal people on how to speak in public"! It takes a lot of energy and stress to articolate my stupid mouth, but I do. The biggest part of my brain is continuously used to move my stupid mouth. But I do. Anger is the key, concentration is everything. It's like the koans of zen buddhism. You are the only one that can save yourself. And you can. Trust me.