Been there man. I was reached out to by a recruiter where they were hiring for basically my dream job. I was able to be pretty fluent with the recruiter, but when the time came to talk to the employer (which was a 3 part interview) I was stuttering like crazy, and because I was focusing so much on my disfluency I was just randomly rambling and I dont even know if anything I was saying made sense. I didn't get the job. LOL But, don't let it get you down too much. You learn from this and toughen up from these experiences. Be proud of yourself for at least throwing yourself into those sort of situations and try and learn from it.