My school / college days were hell. But, as you get older, you learn to not give a shit as much. And, as a result, my stutter slowly got better, and better! So, my advice to you is to focus on everything else. Remember that it doesn't define you, and to talk to people about it. It really helps. Finally, the fact you're talking about it on here means that you give a shit about yourself. And damn right. You matter to a lot of people.