How to not give a f?

Today when I was omw to math clz there was this girl sitting on the stairs reading a book who also is in my math clz. I thought I’mma talk to her. But right before I stop in front of her i couldn’t. I just went past her. I always have this fear of rejection or embarrassment. It’s like I’m afraid I’ll get embarrassed in front of everybody if the conversation doesn’t go well.

All the time I build up different scenarios to interact with people but in reality I’m just quite and almost autistic. But I don’t hv autism