For someone who is stutterer you took on a job that could cause a lot of anxiety. I use to have trouble on the phone which is why I avoided it as much as I could. I give you credit for trying. Did you tell your new employers that you had a stuttering problem? I am lucky in a sense that I am a speech pathologist and a lifelong stutterer so I have a lot of knowledge based on speech issues. I discovered a way to be free of stuttering. Have you tried therapy that centers on airflow. I found those to be the most effective. I hope things work out for you.