How do you guys speak so confidently?

I mean, you find yourselves in a gathering of strangers, but you still find your voice.

I admire all of you so much.
Mine is the opposite. It's not that I can't speak in public, I can but my brain perceives it as a threat.

Then the survival instinct kicks in: my heart starts racing, my lips go dry, my hands get sweaty, and I stumble on my wo
rds.