Desensitization works with this situation. For me, the telephone was always my nemesis. To resolve it, I bought a phone from Ebay and I practiced daily for months. I utilized my acting experience to pretend that it would ring and then i would answer it and start my conversation. Also, I would dial and pretend to ask questions. It may sound silly to most but after months of daily practice, it became boring. I would download soundclips of nosy crowded restaurants and practice at home ordering. This is what worked for me. Just my 2 cents.