Exercise, talk to yourself in the mirror, read out loud, eat healthy stuff, and most importantly, DO NOT DO DRUGS. Your mental health is the most important for a stutterer. I myself am a stutterer and suffered too because of this. I feel like I could be a totally different person if i didn't stutter. And no, God will not help. You have to help yourself. Your stuttering will never go away. You must learn how to control it. The best practice is speaking, speaking, speaking. If you close in on yourself and refuse to talk to anybody, it will only get worse. Regarding drugs: when i was 16 i started smoking and going to festivals, and thought drugs will do good for my speech, since speaking while high on alcohol/mdma/speed would be flawless. But after turning 21, I realised it only changes your speaking for the worst. The only thing i find good are psychedelic mushrooms. I do one session each month and it causes wonders for your mental health. PS: I almost forgot. Meditation can do wonders for you. Try it. And be strong. PS2: Spend your time doing some sort of sport which will increase your confidence. Try kickboxing/american football/boxing.