The only time I got truly nervous was out my very first gig many years ago. We were a terrible band, unrehearsed with the most ropy setlist ever.
Our first "number" was a jam where one of us yelled out the chords, a dreadful din. However I looked up and saw the dance floor was packed with drunk punters shaking their thing.
That was it for nerves and me, if they like this sh1te just imagine if we were actually any good?
Now I don't really get any nerves, just a little buzz if its a good venue. I look at it as a team sport, all the others occasionally make mistakes, me included. Nobody died, just laugh it off.