Statistics reveal that most people in the world are more afraid of singing in public than of death itself! I believe that such a fear is a great one to overcome. It's amazing how much gets freed up in one's psyche (soul) upon facing this bugaboo once and for all - and performing onstage is a lot of fun, to boot!
Some years ago I determined to take the bull by the horns and accept the challenge. I enrolled in a singing workshop in New York City at the Turtle Bay Music School to perform in a live CABARET at its culmination.  I was scared spitless! But, having taught at various colleges in NYC, I knew that if I worked out my performance thoroughly in advance I could handle 'appearing' in public. Singing, however is a whole 'nother thing! Then came the aspect of smoothly transitioning back and forth been the lower tones (chest voice) and the upper tones (head voice) I had observed other newbies hit a screeching sound, which I recognized as sheer terror at that juncture, and determined that I would not be doing any such transition!
I chose an up-tempo song with a non-challenging range: "Fever"! I opted for a key that was in my  SPEAKING  RANGE  - and that eliminated most of the triggers for terror. Then I performed it at home several hundred times over the next few months, imagining a full audience in front of me.
On the day of the show I felt like I should be going to the hospital instead of the nightclub! But I went!  And I performed "Fever" two nights in a row at  the DON'T  TELL. MAMA cabaret.  I was ecstatic! I had done it!  Twice! I even had the audacity to put it (my first performance ever!) on Facebook years later - for exactly this purpose: to tell you, step-by-step, how you could overcome such a crippling fear.