Mines pretty bad too, I'm currently 18. I think mine peaked at 16 and has been decreasing more and more. Lots of people will bullshit you and say it'll get better eventually but I know that will only make you worry more because you want it better now. It's sometimes easier to breathe a bit differently or move your mouth slightly until the words come out. Recently my mind had gone straight to biting my tongue but DONT do that! I've had a girlfriend for the past two years and I'll never know how she puts up with it. For me it helped to make myself unlike everyone else. Dress a bit differently. Walk with your head up. Do things you love. You'll get there in no time. Good luck <3