Social anxiety

my cousin backstabbed me since 2024, she turned all my friends against me (whom btw i found her when she was alone). Ever since then i started struggling with social anxiety, i used to be very extroverted but since then i cant talk. None of my "friends" want to talk to me either, when i sit with them they change their place and etc. As for my classmates, they all talk with each other except for me, i stand and stare at nothing while everyone talks. I am the only student who doesnt talk and stays silent, it got to the point i cant talk to the teachers even. This has been very hard for me i dont know what to do, I cant even concentrate on studies.. even taking small steps is hard for me because others are used for me like this.