I know how you feel, phone calls are the worst for me as well. My mom and I have a catering business and slowly I'm the one who has to talk to the customers so every time the phone rings I try to remember to remain calm and to breathe. Mostly I rattle my "scripted" greeting and even the follow-up questions I know I need to ask. The problems start when the customer asks me a different question or when they didn't understand what I said and I have to repeat myself. Then the stutter gets worse again and I don't know what to say so as you, I start to tell them 'dumb' stuff and try to end the phone call ASAP. To this day I spoke like five times with my best friend over the phone (we know each other for over 15 years now..) and even though she knows me pretty well and doesn't try to say the word when I can't say it, it's still pretty awkward. I have no problem talking to my family over the phone, there was a time where I even couldnt do this. I know this might not be really helpful, BUT you are NOT a coward and there are people who understand what you're going through. It does get better!