NorthStar, I'm sorry you feel so bad and experience a lot of bullying at the moment.
I can certainly remember times at grammar school when I was bullied and really hated the thought of returning there the next day. It's not a good place to be in.

Yes, I think it might be useful if you can find a trustworthy person at school with whom you can talk these things through and who might be able to suggest some ways forward.
It can of course be someone outside school, too, but considering that a lot of the current troubles you experience are school-related, it might be helpful to find someone there who you can confide in, won't betray your trust and is sensible and experienced enough to work on a solution to this issue together with you.

It makes me angry to learn that people call you stupid and other names. The act of doing so is what I would call stupid. I know it's hard, but please try not to internalise these words too much. I also agree with what has been said above in a post - you express yourself clearly, which is already proof that the 'stupid' label is completely inaccurate.

I wish you all the best and keep posting, NorthStar!