A little fear is a good thing. It's an indicator to you that you are getting outside your comfort zone, whether your motor skills or your level of experience. And that being said, the Memphis metro area is not even remotely known as a bike-friendly place.

Maybe you don't have to bike all the way in... My total commute is about 27 miles by the road network, so I drive the pickup to a commuter lot just inside town, park & lock up, off load the bike, and pedal the last 9 miles in to the office. Takes me maybe an extra 15 to 20 minutes in the morning, but I get way more than that time back in the afternoon since when I get back, my "training ride" is already done.

Some other ideas here: http://www.nwanews.com/adg/Style/227569/

There are a couple of good LCIs in the Memphis area... you might look one of them up and see about taking the Road I and Commuter classes to help build your confidence on the streets, as well as pick up some good skills for dealing with traffic and picking a safer, less stressful ride route...

Tom