caught crossdressing by my roommates

I am the monitor of my class and the president of the student union. On the surface, I looked glamorous, but I actually had an unknown secret - I would put on black stockings and boots every night in the dormitory and masturbate while watching pornographic movies. One day, my secret was revealed by some roommates, and they used it as a blackmail to turn me into their sex slave.
At first, they just made me wear black stockings and boots under my uniform and secretly played with my body in class. They would rub my ass when the teacher wasn't looking, or tease my already soaked clit with their fingers. Once, the teacher asked me to stand up to answer a question. There was a vibrating dildo stuffed in my asshole. In full view of everyone, I almost reached climax in front of the whole class.
Gradually, their control over me became more and more excessive. They would shoot their semen onto my black stockings and boots while I was away, forcing me to wear these clothes stained with their semen all day long. But I, as the squad leader, could only hold back my tears and pleasure and obey them.
Now, they were no longer content to just bully me in private. During free time in physical education class, they would pull me to an empty storage room, press me to the ground in front of my classmates on the playground outside, and take turns raping me. They would pull down my pants, leaving my black stockings and boots completely exposed, leaving new marks on them.
During the day, I would appear in every corner of the campus wearing my uniform; at night, I would return to the dormitory and become the plaything of those three beasts. No one knew my true identity, and I could only endure it all silently in the dark.