Learn to speak a foreign language as a child I guess. I never have that fear. I am a little surprised even that there is so much fear. It is about the third topic I read concerning this subject since I am here on italki. So, again, third time same story, when I was a child, my parents went on holiday, to France, Spain. My parents gave me money to buy candy at the local shop. I asked them what ice cream was in Spanish or French, and bought it. So, I am used to speak a foreign language, even when I do not know every word, every sentence. As a child you do not even know that in your native language. Hence I never felt any shame making mistakes, nor do so now. I just talk!
Scrap your fear.