I have developed nerve pain on the back of my scalp, as well as daily awful headaches.
A virus can contribute, but no doctor can diagnose without complete medical history including injuries, dental,
white blood cell count - CBC with differential, MRIs or CT. Other tests may include immunoglobulins, serum, electrophoresis, tumor neurosis factor, monocytes, mast cell, eosinophils.
I agree with John that occipital fibers or nerves are being pressured. There's many very complex involved studies that also point to a host of other things such as neck muscle tension from injury or incorrect posture. Many muscles of neck including the sternocleidomastoids.
Also having pressure behind the nose could be:
Ethmoid sinusitis more so than sphenoid sinusitis (behind the bridge of the nose) can associate to headaches into scalp, pain between the eyes, eyelid swelling, loss of smell, head tinnitus, occipital nerve pressure, neck injury/neck muscle stress, pain behind nose and pain when touching the sides of the nose. Sphenoid sinusitis (behind the eyes) can cause earaches, neck pain.