severe headache that will not go away? advice?

I started having a headache yesterday, and it was bad. I used to get migraines a lot but they would last a few hours and go away. But this headache will not go away. I get up and my head pounds, I walk up or down my stairs and my head pounds. It's on the left side of my head. So I woke up this morning and again, the pounding is starting again. Anyone else? It is starting to worry me. Any advice? Thanks y'all. 💙💚