Driving Anxiety?

I've always been teensy nervous about driving, but about 6 months ago, I was rear ended at a stoplight. Fortunately, I was/am fine. The whole rear of the car was ruined. I have vivid memories of seeing the other driver speeding up behind me, hitting me and pushing me a few feet past the stop light.

I know I'm not a bad driver. Never had a ticket or accident befote this happened. But at times, while driving, I start feeling panicky. When Im on a crowded freeway, I get scared to switch lanes or takean exit. When I see a car speeding, i fear it will hit me. Driving at night scares me because i am overwhelmed by cars headlights.

Has anyone felt this way after a collision/accident? I tend to panic mostly at night or on crowded freeways.