Okay guys I need a little advice, on what to do with this situation..

Okay so there is this girl at my school and she's pretty popular and we go to a small school so everyone knows everyone. And not gonna lie she's been a total bitch to me lately. Calling me stupid because I'm slow, when it was something that was both equally are faults. She keeps bringing it up in front of more and more people and calling me stupid. Even after we were over the topic and I walked to my locker she walked by and said " are you too stupid to open your locker too" I can tell she was saying this in a joking matter but when she keeps going on like this, it's a total bitch move. She does this with things I've done in the past as well, but now we have to be partners in a class together and it just keeps getting worse. I honestly feel stupid for being so emotional 😭 about this but it's really making me feel like total crap... please comment and tell me what I should do.

Also should I feel like a baby for wanting to move seats and having a different partner? I feel like I should just deal with it because that's what you'll have to do in the " real world"