If you decide that it's important for you to go and it's not just a case of nerves, then I like the play "what's the worst that could happen game":

You could get lost....which other than the extra gas, is not that big a deal because eventually you find you way again. A GPS would really help conquer this fear - nothing like turn by turn directions!

You could run out of gas....ok, so make sure you fill up before you go

You could have trouble finding parking....just make sure you leave extra early so you have time to search.

You could get a flat tire on the road....make sure you have AAA - they have helped me a lot in the past!

Now some good things that could happen:

You could really like this doc and he could give you some new ideas for how to approach your symptoms

You could have a sense of pride when you are done that you did it all yourself!!