Your neck and back pain are typical w/ that type of accident, the loading of the spinal column from a lateral perspective can cause a lot of issues with the alignment of your back and the disks there in, also there is are going to be a lot of muscular issues. Your headaches are more than likely related to the fact that you probably kissed that passenger side window and now have a mild concussion. i would see your general MD. Basically you will have some PT and get a Motrin and flexiril regiment with some steroids to help ease the muscle tension. Glad to hear you are all right.