AITA for refusing to go to my student-organized graduation ceremony?

I (22F) am in a conflict with my mother because I refuse to attend a diploma ceremony for my university major this Monday, they won’t give us the degree, it’s just a diploma stating our generation ended. This ceremony was organized by students, not the university, though it will be held on campus

It’s important to note that this student-organized ceremony is the only event for receiving our diplomas. There is no separate, official university ceremony. The only other related activity is going to the administration office on a designated day with your family to pick up the physical degree and paperwork, but that is not a ceremonial event.

NOTE: This diploma ≠ the official degree for my major. As I said before this diploma is only a statement that our generation’s period ended.

The reason I don’t want to go is that my graduating class has a horrible reputation. Many of them have engaged in awful attitudes and have even committed acts that are supposed to be punishable, far more so than other classes. While not every single person is terrible, the other students are largely skipping this event, meaning it will be dominated by the troublesome people I actively "despise". I straight don’t like them nor want to be around them.

I told my mom I wasn’t going, and she called me egotistical, self-centered, and a coward for not being able to tolerate a few hours with people I dislike. She said I was only thinking about myself and not about my family. She insisted this event was important for them and that I was denying them the experience. She heavily guilt-tripped me by adding that as her only child, she has no other graduations to attend.

I argued that it was unfair to guilt me for my decision. She replied that I was being inconsiderate and that she would "keep in mind that I only care about my own feelings."

To defend myself, I reminded her that I’m not a selfish person. When I was a teen, I went along with a Quinceañera party that I didn’t want and didn’t enjoy, purely to make my family happy. She just laughed and dismissed it, saying, "Oh well, it’s in the past now, it doesn’t matter anymore."

The argument ended with her asserting her authority, saying, "You don’t know me, child. My ego is stronger than yours, and I decide we’re not going now because I say so." But despite her final word, her accusations have stuck with me and made me question if my stance is wrong.

My mother believes I’m an asshole because she sees my refusal as a selfish and cowardly act that ruins an important "family milestone" for her, especially since she has no other children (even though she’s attended my older cousin’s diploma ceremonies). I feel I’m making a decision based on my valid discomfort, but her words are making me second-guess myself.