I know exactly what everyone is talking about here, about being afraid of driving. I waited until I was 20 to get my license, putting it off until then precisely for the same reason. I just didn't want to confront it. I thought driving was a chaotic, unpredictable activity, with potentially fatal consequences, even for people who do everything they are supposed to do. I was forced to take a driver's ed course in high school, and of course, those things concentrate on scaring kids into not driving under the influence. They showed me a few movies on the subject; let me tell you, they may be effective on careless drivers, but they certainly don't help when you're neurotic and petrified of getting behind the wheel. I only got my license halfway through college, and that was only because it was a necessity due to my living situation at the time. I was nervous, but I'll tell you how I got through it:
First of all, professional lessons do help when you're starting. The important thing, if you're scared of driving, is really to build confidence. Having a professional in the car with you is a lot like having training wheels on-- it's a good way to give you enough experience to feel comfortable.
If you're like I was, thinking that you don't even have to be the one to make a mistake to be in jeopardy, keep this in mind: nobody wants to be in a car accident. For as many bad or inconsiderate drivers as there seem to be out there on the roads, they want to avoid accidents just as much as you. I've been through a few close calls (not all of them my fault), and I won't lie to you, they're scary. Your best defense is to be alert and knowledgable about what to do in these cases.
But of course, like anything else, the best way to become accomplished is to practice. You can go at your own pace. Start with quiet suburban streets, roads with less traffic, then gradually work yourself up as you become more comfortable with the car. Drive to the local supermarket sometime. Just, practice. I can't stress it enough. The confidence to drive comes from having actual time in the driver's seat.