I have severe acute neck pain in the top right quarter of my back, doctor doesn't have a diagnosis.it comes and goes. what could this be?

Muscle spasm: Unlikely gall bladder, lung/rib disease.

Trigger points: Pain in the midline of the back or around the shoulder blades is usually muscular. Trigger points, fairly specific areas that when pressed reproduce or trigger the pain, are common and muscular. Levator scapula syndrome is a variant near the top of the shoulder blade. Good posture, avoid looking down at computer screens. Try ice/heat, nsaid's, and salonpas hot patches.