If fear is fatal, then you need the help of a specialist. Otherwise, we pull ourselves together and begin to solve the problem. You need to understand what you are afraid of. To be misunderstood? Or get a boorish answer, for example? You must understand that people like you are working everywhere. You don't see them and you don't even know them. She herself faced exactly the same situation, when she was almost wet to her hands and was afraid to call somewhere. And then there was work and the word "must", like a mantra. And here there is no way out, how to pick up the phone and call. The first time is hard, the second, the third, the fifth time you feel freer, and 15 times it is so in general. This is purely a matter of habit. So don't be afraid to start changing and everything will be fine. Just do it;)
It is important to understand what it is. It is highly likely that you are describing social anxiety or social anxiety.
I recommend that you first complete the online Libovitz Social Anxiety Scale LSAS. With high scores, you need to see a specialist in the field of psychotherapy. In some cases, medications are also prescribed.