What Causes Pressure Headaches, Insomnia And Forgetfulness After Accident?

I am 52 yr old female I had a car accident 3 Mar 2011 and air bag hit me and Ive been diganosed with PCS...its 3 mths later and I still suffer problems with headaches, pressure in my head, insomnia, problems concentrating, bad nightmares when I sleep, forgetfullness, loud noises and the list goes on. I have been to the Drs so many times and no one can tell me whats best for me. I am seeing the Nurologist again in couple of days to have the MRI done, any suggestions