Classroom panic

I was in my 4th year of school, I'd been in this new english class two months, very few of my friends were in it mostly people i didn't really know. It was a large class nearly 30 students and we were the top english, the class that were expected to achieve the highest grades. Everyone was out to prove themselves to be one of the best. I felt anxious in this class,a feeling I was not used to experiencing in the classroom. Before this I was as confident as anyone around me. An actor I had performed in many plays with the local amateur dramatics society. Often I was the only person under 18 in the group. I used to love reading out in class, because I knew I was good at it. I even read at Mass in front of the entire school when I was just 14. However that day it all changed. The week before I read an essay aloud on my school culture, because i was the only one who had it done some people were laughing something that would normally never bother me and to be honest it didn't really. However half way through it I felt this nervous sensation, I became short of breath and my heart was beating faster than I ever imagined it could. I made it through it though and pushed the thought out of my head. However it was on this day it came back to haunt me. Halfway through the piece the same nervous symptoms overtook me.I had to stop reading. It spread like a disease to my other classes soon I couldn't sit in a classroom without the fear of being asked to read.My ability to speak in public was something I had prided myself on before this, i could never understand why some people may not want to. More than a year later i still haven't beaten it, I am now calmer in class. But the thought of reading still scares me. It has affected the career path I am choosing. It makes me scared to think this might hold me back. All i can do is hope that in time I will beat it.