Pain in left-back side, under skull.

So, I have been experiencing some pain in the back side of my head... toward left, a little near the ear, and the bottom side of skull. Been experiencing dizziness since a week but pain started couple days ago. The pain almost completely subsides when I am horizontal. Its hard to explain but it kinda feels like there is a vacuum in that part of the head and enough oxygen can't reach there.... when I am completely relaxed when I am horizontal... I find a painful but relieving and involuntary movement in my head, like air or liquid moving.... for only a fraction of a second and then it is gone... It also happens when I yawn sometimes.. I understand I am going to have to take an offline consultation in mine or adjoining city for effective treatment. I just need to know the possible diagnosis, and I want to rule out the possibility that it is just because of stress. I do take anxiety medication, bupropion and oxetol 300 . So a bit used to weird and new things happening for a while.