AITA for cutting off my friend after she got mad at me over something another girl did?

I (17F) had a very close friend (17F). We hung out almost every weekend and always had a ton of fun, had a bunch of inside jokes, and were together constantly at school.
Earlier in our friendship, we had problems with a girl in our class, “Kayla” (17F). She accused us of gossiping about her and lied about us to other classmates. We eventually talked it out, but stopped communicating with her.

Later, Kayla became part of the larger friend group my friend was in. I told my friend I felt uncomfortable, but she assured me she barely interacted with Kayla and didn’t like her either, so I ignored it.
At the end of the school year, Kayla and I both had problems in math. The difference was that I had been doing my homework, participating and genuinely trying, while Kayla rarely did any work.

On the last day, the teacher told me I was going to fail, but told Kayla she would “think about” her grade. I stayed after class to ask about it, and the teacher became extremely rude and started yelling at me. During the argument, she mentioned that she had apparently passed someone “undeservedly” the previous year. I showed her my grades and explained she was confusing me with Kayla. She then said neither of us would pass. Kayla, who was also in the classroom at the time, gave me the dirtiest side eye ever.

I went to the counselor’s office to report what happened. While I was there, Kayla apparently told everyone that she was failing because of me. After i got out of the councelors office, i went up to my classmated and i immediately sensed the vibe shift, but i tried brushing it off. I just told my mom to come pick me up early so we could discuss the situation.
When I got into my mom’s car, my friend texted me saying I had been too harsh on Kayla and that I was the reason she would fail. I was already extremely upset, so I told her Kayla was responsible for her own grade and that I only mentioned her because the teacher had literally confused me with her.
My friend said I had no right to complain because I also had bad grades and that bringing Kayla into the argument was unfair. I tried explaining everything, but she just said “ok,” so I left her on read.
The next day she completely ignored me, so I ignored her too. Another friend who had actually witnessed the situation explained what happened to her, but she still refused to talk to me.
The math situation was eventually resolved and both Kayla and I passed, but my friend continued ignoring me.

A month into summer, she messaged me asking why I hadn’t talked to her all summer. I explained that she was the one who had been angry with me and that I was hurt she believed Kayla over me. We almost made up, but she became defensive again and insisted I was wrong for mentioning Kayla. We ended things without resolving anything.
Now school has started again. She talks to Kayla and everyone else while ignoring me, and some people from her friend group have also stopped talking to me.
I still feel like I did the right thing, but I’m really sad that such a close friendship ended over this. I really try and be as objective as possible but now seeing my ex friend who hated Kayla being all nice to her just makes me sick.I keep wondering if I’m actually the one in the wrong.
AITA?