Don't fake and don't try to act cool, that'll fail sooner than later. Thinking that you are better than everyone else is even worse; you are young and you'll have a lot to learn from a lot of people; that attitude is one the worst you could have. Putting yourself in uncomfortable situations helps, but you need to analyze after why that was an uncomfortable situation to adjust yourself over time and that's not easy to do alone. Trying to do it by yourself is very hard, I suggest you to look for specialized help, a speech therapist that may help you with those questions about techniques and also a psychologist to help with that self-esteem and help you be confortable with your stutter. Good luck!