I can relate to your pain. I use to get bullied over my stuttering. I dealt with it in some form up through 9th/10th grade. There were times where I’d let it bother me. However as the years went by, that gradually disappeared. Once I got to college, it wasn’t an issue. Once in a blue moon, I’d see people laugh or say something snarky if I had to give a speech. I’d usually stop mid-sentence, and just wait until they stopped. They’d shut up instantly. People are just immature plain and simple. You learn over time who to associate with.