I would suggest you to keep smiling wherever you talk, it eases me. And instead of concentrating on the words that come out of my mouth, i try speaking in a passionate fashion, maybe sometimes with accent. The less I focus on words that i am about to utter and more on being passionate, the better it gets and I always try to speak on urge( like we shouldn’t contemplate about the words that are to be spoken, we should start speaking the moment we get a thought but in a passionate way). Read the book “how to stop stuttering and love speaking”