God i suffer from exacly the same thing as you. Sometimes, i don't know why, i can't spell my first name so i use my second, but almost no one knows me for my second so it's really enbarrasing. Other times i can just say it without a problem. For context, i don't stutter much but specially in phone calls, i can't even start by saying my name, it's so BAD and frustating. I really suffer from it at work. I don't stutter once when people call me and know me, but when i call unknow people and have to say my name, i just can't.