I think most of us have problems on the phone. I think th toughest part for a lot of us is letting people hear us stutter on the phone (calling at work, conference calls, etc...). As I see it the only way to get over this challenge is the same way to overcome all hurdles, you've got to just take it on. That said, I think there are better and more organized way to do this than throwing yourself to the wolves a few times and then becoming too traumatized to do it again. I would recommend a qualified SLP who knows about dealing with avoidance situations and difficult situations in general. they would probably help craft something to help you confront the phone. I know a lot of people who just do practice calls when they're feeling scared. They will call up random shops or department and ask a random question or two. This is to desensitize themselves to the fear of the phone and make realize that they can still communicate, even when it's not face to face. might want to give that a try. Even something like calling a shop and asking what time they're open until.