Let's see...I've performed with a group once, and I've performed by myself on seven occasions. (I've only been performing since February.)
I have to say the group dance was the most nerve-wracking, because I was so worried about making sure we were all doing the same thing. I only remember bits and pieces of it and I'm sorry about that because if I wasn't so nervous I might have really enjoyed it.
I was so nervous when I did my first solo that I forgot everything! lol Major case of stage fright, for sure. (Which ended up being kind of good, because it totally changed the way I choreograph.)
The last few times I've performed, I've felt totally fine until the exact moment I've walked out on the floor. My stomach drops, I get that cold feeling, etc. But then when the music starts, I'm into it. I have surreal moments off and on during the whole performance--like every once in awhile I suddenly realize what I'm doing and really think about it--then I'm back in dancing la la land.
Oh yeah...and afterwards, I'm usually on kind of a high. I feel exhilerated and I'm sorry it's over and I want to go back and do it again.