I need some advice on how to deal with bullying within school

I am basically hated by everyone for no reason. There is only 35 students in the class so it rarely small and rumors travel fast. For example, we all went out to a bar 5 months ago and I got really drunk. I didn't say or do anything crazy at all. Just had a good time dancing and even got a dance circle going. No bartender or bouncer ever said I was an annoyance. That night a guy in my class wanted to drink with me and ended up getting blacked out drunk.

Somehow it's my fault according to my classmates. They even started a rumor that I drive home drunk. I'm not well liked even though I don't do anything at all. Most time I just chill and ask people about their day.

Another small story is that a girl in my class that I liked also randomly started to dislike me. I moved on thanks to this groupchat but there's a rumor that I tried to sleep with her because i drove her home from the bar. All of her friends and guys hate me now. All of this happen 5 months ago when I used to hang out with them. I'm still treated as an outcast everyday. Went to volunteer event with some of the students and they all made fun of me for 2 hours straight for no reason. And they reference that night.

What can I do? It's affecting my mental health since I can't distance myself from it. Also I have notices I don't have that same confidence I had. I used to be able to talk to anyone including strangers. Now I don't trust people anymore. I don't even like joking with strangers and I am very closed off. How do I cope?