I also had a mean teacher in KINDERGARTEN! She humiliated me because I didn't understand how to properly use scissors. She was telling to me in front of the whole classroom that she would glue a paper on me with the word "Donkey" on it. That fucked me up, and because of it, I stutter ever since. Children were not easy to deal with too, the mocking, the bullying, the laughing and all of that fucked me up. 20 years later, I still stutter but much less than when I was a kid, it also highly affected my grades due to loss of self-esteem. I got accepted to a university, doing what I like, computer science, but still, my GPA was fucked. It's when I was about to get expelled that I seeked help to my university's counselor, she helped me A LOT. Just by talking, she could understand my problems, gave me a boost in confidence, and it actually helped me in having a self-esteem, and it also helped me get better grades. Now, I graduated, started a job as data scientist that I love, delivering outstanding results, and currently looking for a master's in Europe. All of that, while I'm in Morocco, a third world country in Africa which doesn't have any stuttering awarness, nor any mental health awarness. Don't lose hope, you can do it, try seeking help to your university's counselor if possible, and you will feel much better.