Yes, no such anxiety since then. I had some other stuff going on too causing insecurities that might have contributed to the attack. Of course there is still some normal excitment before an act but it always relieves when I get into it. I've even sang in front of high school (during lunch in the canteen though so it was quite casual event) when performing a song with a band. Though it makes me gringe a little when I realized how amateur I'm still at clean vocals but it was still some good performing experience :D

And I also sang in a choir during high school. It's a lower stress environment when performing since the spotlight isn't directly on anyone so I can recommend it as you are into singing as well if I remember correctly.

If you find a choir in your school feel free to give it a try.