HEADACHE BEHIND BACK HEAD. Other issue.

I AM FEELING HEADACHE IN MID SCALP AND BACK OF HEAD FROM LAST 4 MONTHS. HEADACHE OCCUR IMMEDIATELY AFTER EATING SOMETHING. BRAIN FOG ALSO I FEEL.It feels like needles in back head some times on side of head...after exercise or after going to bed it get cured automatically. I CHECKED MY BP SOMETIMES IT COMES 140/90 SOMETIMES 130/80 125/77 . READING MOSTLY COMES IN RANGE 130/85 . I WANT TO KNOW WHY I M FEELING HEADCHE a. sometimes i feel that anxiety harmones are realeasing in my stomach. . headache mostly occur after waking up. my lifestyle is ok nd i dont eat outside food. can my bp come to normal level permanently and is my headache due to blood pressure or any other issue.from last some days i am taking medha vati of patanjali my headche occurs but less frequent. What should i do. What is possible reason of this type of headache. My all blood test normal tmt echo ecg normal. also left hand bp comes low and right hand high average difference of 10-15 point.