Headache None-stop

For the past three days for some reason I have been suffering from a major headache and I’m not sure what it is. I thought it was lack of sleep but after staying home for a while and catch up on my sleep it wasn’t working. Then I figured it was the lack of nutrition but yeah… that isn’t it. So I’m confused as what it may be. What else can it be? I’m not very fond of doctors but it think I may have to go see my doctors.