pregnancy headaches/migraines

I have been dealing with headaches almost every single day for the last month. I am 5 months pregnant and assumed it was water intake related. So I have increased my water and eat throughout the day, but like clockwork every afternoon a shitty headache kicks in and it leaves me feeling awful. Today it has been 100% worse and I feel as if my head is being crushed. I can't be in the light and every time I move my head throbs.