Pain from shoulder to lower arm after a bad fall. How can I relieve the pain?

A drunk driver crashed into me at a high speed. My vehicle was hit, flipped over and landed on the passenger side. I was in my seat belt, the air bags deployed, but I landed against the console on my right side. I experienced a great deal of pain from the swelling and bruises, but had no broken bones or lacerations. Nothing showed up on the initial X-rays. At this time,(4 months later) there is a lot of aching on that arm from the shoulder to lower arm and the arm does not respond like my left arm does. What should I be doing to help myself?