Talk to Internal Medicine on Severe Headache

Asallamalaikum,Docs Two days ago, I woke up with a severe headache around 11 AM. The pain worsened to an unbearable level. I took a painkiller but vomited soon after, possibly expelling the medicine. BP remained normal (110/75–120/81). Later, another painkiller with pain balm gave slight relief, but pain persisted, especially when moving my head or neck, feeling concentrated at the center. Doctor diagnosed electrolyte imbalance (I had loose motions three days prior). After two days of ORS, pain has reduced but not completely gone. My question: Why do I still feel heaviness over my eyes and slight pressure in my head despite improvement and continuous ORS intake?

No previous medical History as such.