i have severe headache since last 5 years,pain located mostly at the occipital area,i am experiencing a full time severe headache along with short term memory and attention disorder,trying to concentrate triggers the pain,which further leads to distracted attention and short term memory loss,PET scan ,MRI(Veno,Arteterio ,all with and without contrast )taken.all result shows normal ,medicine taken for migraine and psedo dementia, depression,as per doctors diagnosis,no relief ,not even 1 % relief,pls guide me as what to do