AITAH for not being kind to friend, who doesn't care about me anymore ?

So.... this is my first reddit post, I will try my best:

I study at a small university and quickly got some friends there to hang out and work with and that for a years now. One friend of mine, let's call her Jess, is really extroverted and likes to tell you her opinion and so on, but can also be harsh if you don't watch out. I didn't mind that at first, she can be sweet after all.

Last semester was a bit difficult: I passed an exam Jess didn't pass. I told her it's alright, you can do that the next time (we got 3 'attempts' for one exam) because she really can. I got a call this eve, where she told me, I would be an awful friend for not crying with her and for studying differently. I thought I didn't hear that quite right: I went to library often that year to concentrate better but she didn't want to come, so I went alone. Now she complains ? Let's say I was confused but not worried.

Now ,after Christmas break and not seeing each other for 2 weeks, she was weird. Not talking with me, not even saying "Happy New Year" when I tried to talk with her and looking at me like 'Please not you now'. I sat with others then and she approached me out of nowhere, asking for my grade and points of the last exam. I said, I don't know and I really don't wanna tell her ... maybe a bit harsh, I admit it, but I was so annoyed from that, college isn't a competition. Now she ignores me and tells me, I won't care for her and the friendship and would never be nice to her and that it wouldn't have been the first time I yelled at her.

She often goes up to me with rude comments, also in the past, and said then it's just meant fun or as a joke. For example: You can't know about that one, we talk about adult stuff (thanks for pointing out that I dont got a boyfriend right now) or 'Yeah I know you don't wanna spend time with me, you are all awful' (for an event I didn't had time for).

Now she wants to talk with me about it tomorrow, but already told me that I am just not worth the effort and that stresses me out.

AITA for giving her the same medicine (and not even that harsh) or am I blind or something ?

For context: Our college/university is pretty small, so everyone knows everyone, so the conflict would just be pure stress.

(English isn't my mothertounge)