Why am I so scared to talk on the phone?

Whenever I pick a call or have to make a call, I get so scared to answer. I don't know why. I'm afraid to say the wrong words. I can't seem to stop my train of thoughts. I prefer e-mailing because talking on the phone is just too much fear for me. Does anyone have this problem too? I know talking on the phone seems simple to other people but for me, it's really not simple. I just freak out when I'm holding the phone and can't seem to say the right words. I don't want to mess up. I sometimes get scared to talk out loud too. My voice stutters and my knees shake when I have to talk in front of a crowd. It can be a small group of people and I'm already shaking and stuttering like crazy. I tried my whole life to control my fears. It's like I know what to say in my head but I can't seem to say it out loud. My mind is all scatttered. I try my best to just relax but sometimes it gets worse. I like meeting new people and friends. I don't want this to take over my life. I have to deal with public speaking for the reset of my life. I do have friends and I'd be talking to them normally. I don't get why I get so shaked up on the phone. I have gotten ...2% better but that's not much difference. But then again, every step counts. So I'm trying my best to stay calm and just talk. I hate awkard silences. I hate when no one talks or answers after I ask a question or talk about a topic. It's just weird. I do come on strong when I say certain things because my emotions overpower my mind and my voice just breaks out in strong words. I try not to say words that will hurt people. I love to help people with my voice and the actions I take. 90% of the times I don't think before I say/do something. I know it's bad but I do want to STOP & THINK before I say/do something that I know I wil regret soon. SO PLEASE HELP ME? THANK YOU FOR YOUR ANSWERS! :) I know I'm not alone. I know there are sooo many other people out there feeling the same way I do and having the same problems I do so....STAY STRONG even when times are tough. Even when struggles and fears are tripping us. I have to face my fears. Stand up to them. It's a life battle. ;)