Yes PLEASE write a letter to your newspaper- or even ask to be interviewed for a small article! It might help someone, somehow, or might make some driver think for just a moment.
See if you can get license plate numbers as offending cars drive away, and report to the police. Report to the police anyway and tell them your story.
You never know where these efforts might lead- they could save some future biker's life if people are made more aware of what's going on.
Meanwhile...are there other safer roads that you could ride on in your area? Bike paths maybe, or rail-to-trail paths?

I'm so sorry- it's hard to believe that people act this way.