You will need to search pertinent state and federal laws to find out more on breach of confidentiality laws. Typically these statutes will hold the doctor liable for the breach if he, without explicit consent from you, release your information to a third party and the conduct is not justified (such as release it to the insurance company).
In my opinion the biggest problem is the injury. You have to prove that you suffer either a physical injury or emotional distress. If it is an emotional distress it has to severe.