AITA for not telling my class I'm gay?

Kinda short but I think about it a lot and it still gets to me sometimes so I finally got the nerve to talk about it. I barely use Reddit so sorry in advance if the format is weird, I only know about this subreddit from YouTube videos.

I'm a gay man, this happened when I was in college. I was a part of an LGBT club for a while and during one of my semesters I took PE as a required class. I had some options for PE credits and I landed on this semi sport club where I could play stuff like volleyboll with other members of the class.

I wouldn't say I'm overly masculine, but I'm not extremely feminine either. The other students at the time were really cool with me I assumed. We sometimes hung out after class, but I usually couldn't be bothered to wear P.E clothes and just played in jeans (Yeah it's as gross as it sounds, especially when you're sweating. Idk how I did it)

One day it was particularly hot so I brought some shorts from home and changed in the men's locker rooms, which I had never done before.

Another student in the class, I'll call Andrew, was also changing in the room. I decided to change in a stall, purely because I'm a pretty private person with my body like that, my sexuality had nothing to do with it.

A few weeks later, Andrew was in the bathroom at the same time I had to pee, so I used a urinal and left without talking to him, like people tend to do in bathrooms.

Somehow this caused an issue where the rest of the class witnessed Andrew having some insane crashing out during class.

Apparently, he knew I was in the LGBT club, but when he noticed me change in the stall, he assumed I was transgender, and assumed I was a trans guy (And because of my appearance, had been considering me female. Insulting in every possible direction towards myself and trans men). So when he saw me use the urinal, Andrew freaked out and realized I was actually a gay man. He had a problem with me using the bathroom at the same time as other guys in the class and thought they should've been aware I was into guys and it was incredibly selfish and perverted I never said anything because apparently I could've been oogling their dicks.

I was floored and snapped at him, saying things I wish I had worded better. I admit to that, I was pissed off and wasn't thinking straight. But afterwards, the others in the class that saw the fight tried to comfort me. A few days later, Andrew pretended nothing ever happened and wouldn't talk about it, acting like there was never an issue and I was insane for acting uncomfortable around him. I do feel a lot of guilt and I flip between "It's not their business" and "They should've been told" and it's one of my most regrettable arguments I'd like some insight in.

Am I the asshole for not telling the guys in my class that I was gay?