Im affraid to accept some "job" opportunity bc of phone calls

Im affraid to accept some "job" opportunity bc of phone calls Hello, I have a chance to accept some voluntery work, which can have big impact on my career later (some very good references). This job is all about talking on the phone with people, organizing meetings and involves also some chatting with people in the office. How do you confront this fear? I know I have to start somewhere, but just thinking about answering phones gives me stress. I really want to do this, I am just affriad I cannot do it. What is your advice? My stutter is pretty severe when I have to talk to strangers. ​ Thanks a lot!