Do you have tenderness to touch if you press on the bony areas behind your ears ? The whiplash effect of a body check injury can mess up the upper neck and throw the brains blood flow system out of wack.

A Physical Therapist or upper cervical chiro can often help. You would want somebody who knows how to do gentle therapy, gentle traction and mobilization of the cervical vertebra, to help the cervical vertebra to settle into proper place and strengthen. It also requires learning to sleep with good head and neck posture.

Have you tried any dietary changes ? There is a diet called the anti-inflammatory diet. Some have found it very helpful.
Google 'anti inflammatory diet migraines' You will find a lot of information and testimonials.