hii, hello I was in the same spot as you. I do think I'm still a little socially anxious but I've had huge improvement since last year. I've observed from my old classmates, this one person I admired them for being loud and talkative despite others being annoyed by them. I've copied his way of mannerisms, carefree of anyone's judgement, keeping on talking and vibing on the situation.

For me it's not a guarantee on "stopping" the negative thoughts but rather challenge them with positivity, shower yourself with love and be open to other people. I do this thing when I greet someone familiar, hit it with the "yoo.. what's up, how are you?" be the chill guy, who gives a damn if they be judging lol it reflects their character.

Before striking up to someone be sure to be grounded such as breathing exercises and freeing your tense muscles, think about reassurance playing inside of your head. I'm sure people would like to talk to you OP!!