the feeling of wetness at the base of my skull

I have undergone 2 cervical fusions the first fusing c6-7 in 1990 and the 2nd fusing c5-6 in 1999 which resulted in a "nonunion" or "failed fusion".  My problem is primarily this.  When I sit for any length of time such as at the computer for more than 10 minutes I get severe deep deep pain at the base of my skull/neck and along with it there is the feeling that it is wet in that entire area.  The wetness does not present on the skin it is just a feeling that is within the body that is very deep.  The pain that I get too takes my breathe away and when I go to move I must do so very very slowly and I grind my teeth the entire time until I am out of the position that caused the severe pain.  Does anyone have any idea what causes this severe deep deep pain and the feeling of wetness over the neck and upper back area.