I am 16, so I didn't go through this for very long. Up until I was about 13, I wouldn't even walk down the street with my head up. I was terrified of people and talking to them, I was the kid that hid behind her mother's legs or skirt when she was little. It was pathetic. I was always being yelled at by people for being so quiet. They could never hear me, because I was too "shy" or "scared" to talk to them.
In grade 6, 4 years ago, I was in class and my teacher called on me to answer a question. She was a major biatch, and I was terrified of saying anything. When I went to answer her, it came out so quietly that she didn't even relize I had said something. The second time I tried, it was loud enough for her to notice that I had attempted for her to hear me. Maybe she was in a bad mood or something, but she yelled at me so badly for not speaking up. I was so embarassed and my eyes welled up with tears. She asked me how I thought I was going to get through life if no one could ever hear me. The next day she assigned us an oral speech to present in a few weeks. I still think to this day she did it just because she wanted to humiliate me further, either that or try to get me to speak up in a really cruel way. I was an amazing writer so I wrote a really good speech, BUT I knew I would have difficulty presenting it.
When it was my turn to present, I got up completely scared shietless. She made me repeat things up to 6 times until it was at a volume that was reasonable for everyone to hear. Once I and everyone else in our class had finished presenting, she chose me and one other girl to go into the finals. For the finals I was required to go in front of the whole school and present. I was basically forced to present or I would fail my oral mark. I ended up doing it, and came in 3rd out of three people LOL.
When I was standing in front of 800 people presenting my speech, I looked over everyone and realized that they wanted to hear me, that they wanted to listen. It boosted my confidence, (not to the point where I was 100% comfortable speaking, but a lot more than what it originally was.) That same teacher got me to present several more times, in front of a whole intire congregation, in front of my classes, and in front of the school staff. By the end of that year, I was basically forced to overcome my fear!
It was a crappy way of getting through it, and I will tell you now that hell no, it was not easy! There were many times when I wanted to crawl under anything and die, but I was concerned more about my marks than anything at the time.
There are probably better ways of getting over this fear, but for me that's the way I got through it. Now teachers are telling me to shut up and that I am too loud
I think this was something I aquired when I was VERY little. I mean, I remember being like this when I was 4 years old. It had a lot to do with self-esteem and my fear of others.
What I suggest is that you try to find within yourself what your reason of being afraid to speak to people actually is. Try speaking to a doctor about your problem. He/she might be able to offer some insight as to what the real issue is behind this, and may even be able to offer some remedies to overcome it. Try practicing as much as you can, even if it is just with your friends or kids.
The way you present yourself is very much in the way you speak. Speaking loudly, clearly and strongly shows that you are assertive and have confidence in yourself and opinions. Especially at work and school, this is a quality that you should have.
If you feel that this issue is signaficantly interfering with your daily life and your work or school habits, then make sure that you get this taken care of immediatly. No one should have to suffer because of this.
Sorry that this was lengthy, but I thought I should share an experience of my own to show you that you aren't the only one who deals with this, and that it can happen and be overcome at any age.
Hope some of this helps and good luck!