In the early days of The Doors, lead singer Jim Morrison was so nervous he faced away from the audience to sing.
When Elton John was a rising star, his manager told him to keep playing the small gigs; the big audiences could wait.
When you face the audience, two things are going on: the vocal and the physical performance. If speaking on stage fills you with dread, start by recording voice notes on your phone. This allows you to perfect arguably the most important half: your voice.
You can wave your arms and pull faces while practicing; no one will ever know. As your confidence grows, consider sharing these voice notes with friends or on social media. Turning your back on your audience to perfect your craft might just be the smartest move you make.