Sentences starting with a vowel are tough for me. And I have the exact same problem with when you know it's your turn to talk and ESPECIALLY when I'm at work and visitors are there and it's a bunch of us in a room and I know I have to introduce myself, I struggle like no other. Because I have to day my name and there is no secondary route that I can take to cover it up. One thing that helps me get past it sometimes is when it's my turn to speak, I kind of have to exude a little confidence or maybe even do sometimes to break the ice. I've even dropped my water bottle on purpose but made it look like an accident and hope someone who knows me jokes with me about it. That way, it kind of takes a bit of the pressure off of the presentation or task at hand for just a second and makes ME feel less tense. It probably makes no sense to most but it's just our brain is constantly running through scenarios and I try to find what might help in the moment.