Stuttering is not a disease. It's a disorder, an irregularity, disturbance, or interruption of normal functions. . You can't take antibiotics and kill some microbe causing it. It's probably something physically mis-wired within our brains. And no, that does not mean you're mentally fucked in the head. It's more akin to disorders where something isn't quite working 100% in the brain, such as depression or even schizophrenia. No that does not mean you're psycho. But it means that treatments that work for those sorts of disorders may work for us. That includes drug therapy, mental health therapy, and speech therapy. That means hard work and not an instant cure. Maybe someday we'll have nano robots that can go in and rewire neurons, but that's not going to be anytime soon. You are a normal teenager. Everyone has something that affects them. Yours happens to be speech, something you use every day. I encourage you to work on your mental health - preferably with a therapist, but I understand that there can be limits or shame associated with that. When I was going through some rough patches mentally, I found reading articles and listening to some mental health podcasts helped me narrow down what I believe were my issues and that has helped. Something similar may help you as stuttering can be deeply tied to our self esteem and self confidence and our attitudes.