Anxiety is no fun. I do not like the idea of phone calls, either. I never answer phones, or dial out. (Could probably save myself a bill by ditching the phone, right?)
I understand where you're coming from, and hope your anxiety let's up enough for you to do what you need to do. Remember 'this too shall pass'..in any situation where you feel anxious. The phone call will be over as soon as you make it.
Best of luck to you!