I can relate to everything you wrote. I've been there too. The bullying, the shaming, the persecution...

I think that "reserved" is perhaps the right word, instead of "shy". You keep your emotions to yourself, and that's not a bad thing.

I do that too, in order to protect myself. If that bothers people, then it's their problem, not mine.

Those people who say you are "shy", they are ignorant half-wits, in my opinion. They are simply uncapable to produce a spark with the couple of neurons that inhabit their skulls, and therefore are unable to process information and understand that there are people in this world other than them, with different interests and needs from theirs.