It's been 2 weeks and still have headaches

It's been 2 weeks and I can say that I have slept for like 4 to 6 hrs a day after my shift but the problem is I am still having headaches on my shift around 12mn to 2am and wont be gone if I dont take meds or slept it in then after I woke u paround 12nn or 1pm my headaches are starting again. They just pop up randomly and it started only when I begun my night shift. I can't just take pain killers everytime 😮‍💨