Headache when going out. Cure for it?

I have headache problem from last many years. I always have headache when I travel wheather It is by bus or car. I have headache also when I go out like market etc mostly in afternoon. And I have headache also when I take any exam or do any straining physical activity. I had headache almost everyday when I was working in bank often starting from afternoon 3.00 pm or 4.00 pm and sometimes I feel nauseous after getting headache and vomit also. And headache goes away when I sleep in night and on next day it goes away. Headache starts from middle of head sometimes goes to right side sometimes left and sometimes full head. What is my problem I am fed up from my headache problem as it hampers my daily life. What is the problem and cure for it? Thank you!