Most likely you are experiencing what would be considered something along the lines of a bipolar episode.

First of all lets start with the car thing. Its possible that because you are not reaching deep enough restful sleep your mind is having trouble with its motor capabilities.

Your mind when it has racing thoughts means you are pretty much on the way to mania. However, you can control your thoughts. The only way I know of that works is to simply slow everything down. Sitting outside on a sunny day. Walking. Doing things to calm your mind essentially. Watch a TV show that does not interest you at all...maybe a children's program. Work on controlling your breathing. Take a nap in the mid-afternoon. Ready yourself for the nap by taking a long walk and eating some food with protein in it. Put your body to work on basic everyday tasks while letting your mind calm down...that sort of thing.

Overall, keep in mind that you are not crazy. No one truly is...in that they still can control their mind. Let your subconscious have control so you can get restful sleep when you need it. Your active mind will try to control things around it too much if you let it. You need balance in all things.

I haven't studied sleep medication enough. I am concerned that it may affect how your brain works when you sleep. The brain has an active mode and inactive mode. Its possible that the sleep medication might interact negatively with the active mode would be my guess but I'm not sure.