I suffered the same pain with severe pressure in my neck and head. They did a cervical MRI and found nerve root cysts which cause head pressure. They are VERY rare, but a MRI is the way to go.
MRI scan would be the best method of investigation, for diagnosing the present condition.
Till that time , please apply a collar, so that it gives a temporary support to the neck muscles and doesn't irritate them or causes pain.
So please update me , about the MRI results, before i give further opinion.
update: just thought i should give an update. The two bones at the back of my head (behind my ear) hurt too. When i press on them it starts hurting and some spots are worse to touch. The headache has been better, i have had 2 days this week without headache which seems like an improvement. I'm very worried about having a brain tumor but the people around me all say it could be due to the way i sleep, or sit behind the laptop. No one is giving any other diagnosis