It might be a combination. I think that's why your T asked you to call a psychiatrist. But no matter what, things can't get done if you don't do them. Most of my fears was fear of being afraid and my therapy helped some with that. I do most things now whether I'm afraid or not. Some things just take doing them to get less afraid. When things turn out okay then they can be repeated and the more they're repeated, the easier they are to do, like riding a bicycle.

I was always afraid of the phone too and calling and when I was your age and had to call a clinic because my T told me to, I called and was put on hold forever. I was afraid to hang up and held until the "disconnect" tone came on like 10-15 minutes later! I didn't know what to do so called my T and asked her. I was afraid the clinic person answering the phone would get mad I'd called back or something, recognize it was me. My T explained it like nonanxious people see it (including the clinic person answering the phone) and got me to call again and I was successful that time. Maybe you can set up a period and call your T, then the psychiatrist's office to set up an appointment, then the T again? Break down what you have to do and surround yourself with comfort or rewards or whatever would work for you.