I used to go through this exact same situation when I was in highschool. I would fear the days I had to go to English class. Your description brings back some painful memories for me. I've had times when the teacher calls on me to read and I block so hard when starting the first word that they think I'm ignoring them. A pit in my stomach would form, heart beat would increase, and my throat would tighten. I dreaded the days I had to speak at all in highschool. My recommendation for you is either, take that shit head on, or speak with your teacher. Either own your stutter and fuck what other people think about it (I know this can be difficult to do) and read aloud anyways. Or speak with your teacher and make some other arrangements where you don't have to read aloud. I never did either of these things, I wasn't proactive about it. I lived in fear my entire highschool career, and often avoided sitiations where I had to speak. Just know, your not alone in this. My highschool experience was heavily tainted by my anxiety and depression I went through due to my self consciousness while speaking and reading out loud. In fact, it still shapes the way I approach situations today. It had a big impact on me. Take it one day at a time, and don't be too hard on yourself. I know exactly what your going through, so don't be afraid to PM me if you need some support.