Always felt threatened at school - My psycological problems

When I was in elementary school, I always felt threatened.

I was involved in a trouble and cried almost every day.

In many cases when I was scolded, I thought that I had behaved perfectly, so I didn't know why I had to be scolded. It was not fair. In this way, I was panicked, I cried, screamed, banged the floor, the wall, the doors, knocked my head into the wall, and shouted aloud with incomprehensible speeches.

I then had no idea that I had no idea of what I behave is like.
In classroom I said the right answer before the teacher says.
I kept silent in every day cleaning at school even when communication was required, because I had been told that we must not "chat" while cleaning classroom.
I didn't know I could speak in classroom when the teacher told me to do so.
I couldn't tell the difference between a chat and communication required to collaborate.

The thing I learned then was I would be scolded, bullied, ostracized in classroom whatever I do, good thing or bad thing, what ever I speak, wherever I sit, stand, walk and run.
The next day may be my last day. I often thought in elementary school, junior high school, and high school.

As I advanced to junior high school and high school, circumstances had become much milder, getting able to feel that some classmates acknowledging my personality and characteristic, as I made it in tests and athletic meets, although I didn't really understand the desirable relationship to be friends and I was still worried about human relationships, probably with communication stresses and peer pressures.

I was not apparently persecuted at school, but always feeling threatened was big enough a problem which prevent me from communicating and doing things confidently in public.