Hey nervousnellie (LOVE the name),
Can relate to what you're saying. I'm a learner driver but I hate driving because I always think I'm going to swerve and hit someone, so I try to stay outta the drivers seat.
Changing your thinking...probably won't happen for AGES (sorry to crush the hope for an overnight cure and boy do I wish there was one) but it should happen if you stick with trying to overcome it. I don't know how much I could help but just to say that you aren't alone in thinking scary things. But life does go on.
Cheers