Is it okay to speak up when you feel as though your teacher is treating you wrong?

Yes, it's okay. Teachers are humans too. They make mistakes and may not always be conscious about how they're acting. If you feel like your teacher is being unfair, you have a right to bring that to their attention, and if they refuse to listen, you can go to higher authorities. I have brought mistakes up to my teachers before, and they were grateful that I brought it to their attention. If you are afraid or anxious about speaking to them in person, try emailing them to take out the face to face contact with them, and maybe it will be less intimidating.

Yes, of course. If you feel like you have been wronged, always speak up and stand up for yourself. If you don't, they'll continue to think that it's okay to treat you that way. And that's not okay at all. I understand that it may be a scary thing to do to stand up to a teacher (or anybody, for that matter) and that it takes a lot of courage, but don't let yourself go through something like that. You have every right to speak up if you feel that you are being treated in a wrong way. You got this!