it sucks..
I can feel your pain... I don't think most teachers are "out to get anybody" but because SA and shyness are really looked down upon, especailly in the US, it just makes matters worse....
I remember when i was in middle school, around 6th grade, I got straight A's in every class for the whole year. The only class I got a B+ in was Math.. It wasn't because I did poor on my tests, I aced them. It wasn't because I didn't do the HW... It was because of my "lack of class Participation" so the teacher gave me a B+.......
I even went out of my way to raise my hand and particiapte in class during the last semester/quarter/marking period.. i don't remember what it was called now..............But that wasn't enough.........So instead of 7 A's, I had 6 A's and 1 B+...........
It sucked cause I worked hard all year for my grades and I even went out of the way to try and participate more in class... I raised my hand, got up to the board, answered questions and I felt proud of myself...
But none of that mattered because even though my tests averaged out to about a 95, my HW was around a 95, my assignments and quizzes were around a 95..........My class participation in that final quarter was still like a 25........ I didn't get it and still don't get it to this day....
Maybe I would have said something to a teacher, parent, my family or anybody but I never liked to speak up, so I got my 6 A's and 1 B.....
Now that I look back at it, i always though I was too hard on myself and my father was def very hard on me.......................so sometimes I think "i'm never good enough" because of those factors.....
but maybe this teacher had a profound shaping of my outlook on life.....Cause even to this day, at 30 years old, I don't believe in that old theory that "hard work brings great rewards.."
Because at the end of the day I'm the one overlooked for jobs, and promotions not because I don't work hard, don't learn things, don't have skills and talent, but because I'm the person who doesn't talk that much, doesn't socialize all that much, and am more or less a quiet laid back person most of the time.
To me, hard work is great, but if you can't really talk, it usually leads to burn out and anger because others who don't work as hard seem to always get ahead.
On your topic, find a way to speak up more, even if it means you have to study more than anybody else.. Because from my perspective, if you don't talk, people view you as less of a person and talent than everybody else who can talk.