Please help me become less self conscious

[Binny36]

How do you do it? I’m really struggling with this and worried it’s going to impact me further as starting new job.

Think to yourself whether you go around judging other people all the time, or indeed spend that much time thinking about them. I'm guessing probably not. And you probably are quite kind and understanding of other people. That's how people are thinking of you. Not much, or just kind thoughts.
Also just give things your best shot, if it doesn't go well then at least you did your best. It couldn't have gone better. No point applying hindsight - why didn't I do this or say that. The moment has gone.