I need help - Anxiety attacks because of speed and fear of dying in a motor vehicle accident?

In 2005 I were involved in a pedestrian knock down. I were the driver of a ambulance and on my way to a motor vehicle accident, an african man ran over the road and we collided (he died on scene). The thing that is getting me down now is that I have a severe fear of speed and I have this believe that every time I get in a car, I'll be in a accident and I'm gonna die. I have been working in the medical field for 6 years now and I have seen all the different ways people die in an accident. I work for my husband who owns his own ambulance service and I have a three year old daughter. I went to see a psychologist a few times, but he just keeps on going into my childhood and not into my problem. Does anyone have the same problem or any advice for me... Please, it is even affeacting my mariage, I don't know what to do anymore, I am now stuck in an office at home and I feel like a bird in a cage. I hardly ever leave the house and the walls are starting to narrow in on me.....