When I tilt my head back the 2 arteriesin the back of my head get compressed making me fell disorientated and sick. Can anything be done about this?

Are you sure? What 2 arteries in the back of your head? Are you sure about this? Have you had arteriographic studies that document this? Where the radiologist did an injection in neutral position & then with your head back? Was the occlusion total or partial? If that's true, someone could kill you just by holding your head tilted back. Those arteries are vital for life. Please repost with more details.
See vascular surgeon. Positional compromise of the vertebral or basilar arteries is often associated with atherosclerosis of the larger arteries that supply those arteries. Partial blockage of those arteries by atherosclerosis or by problems in the cervical vertebrae may be treated. See a vascular surgeon,, who can arrange for appropriated studies to define these issues.