Headache with unpleasant feeling.

Hi, For last one month Iam having a headache which more feel like pain in nerves of brain and pain in back side of head(at certain point that I can locate). The pain is not severe but it keeps there most of the. Also in the evening if I sit idle I feel weakness in my legs and feel unpleasant. I am taking medicine like amitop,naproxen but it is not going away completely. Also this weakness and unpleasant feeling comes when iam sitting Idle or normaly doing nothing. If i take a walk or running then everything seems good. Also I feel pain in head(on the back side) most of the time when Iam standing up from sitting position. My reports for CT Scan , Hb, LFT, KFt,lipid profile are completely normal. Any help what can be the reason. Medicine line Amitop, naproxen are not completely helping in this pain in back side of headache.