Something is causing this, probably some type of phobia. I've dealt with phobias over the years, and have beat them all. I found that by just doing what I was afraid of, got easier and easier. Write down one of the numbers you need to call, and try not to think about it and call. Worst case scenario, you hang up...no big deal. Tell yourself "this won't kill me" and just do it. You have to, and I can promise you it will get easier and easier and then it will be gone! A lot of us won't answer the phone if we don't recognize the number, but it's not due to fear. Keep telling yourself "I'm in control, this is my phone", nobody can hurt you thru the phone and take control. The more confident you appear in any situation the safer you are. Just start with calling your hairdresser, just do it, don't think about it, do it. Hope this helps. If you want to write me privately, I can tell you of the phobias I had to get over. Take care......
i don't know what causes it...but i know i'm the same way. i get really anxious about talking to family on the phone unless they are really close family. if i don't recognize the number...i don't answer. i generally avoid calling people at all costs. the odd thing is that i'm not "bad" at being on the phone and i'm not really anxious when i'm on it.
i don't know what causes it...but you aren't the only one.