Dear BirdieChaser,
I have many car anxieties but not the same as yours. My father always liked to go fast and cut in and out of lanes and get ahead of everyone. As a child I was terrified of this. Even now I feel fear and sometimes dread when I am in a car being driven by someone else. I think your thoughts and feelings are completely understandable. Wish I had something helpful to offer in the way of advice, but sadly I am at a loss. Hopefully others here who struggle with the same or similar things will have some helpful insights to share with you.
Sincerely yours, Yao Wen