@silo_bear I've been there, it's awful. I'm in the US, in a major city with a university hospital system. The emergency room is useless. If you have access to urgent care, they may be able to prescribe something or do an infusion.

If available to you, for long term planning, get in to see a neurologist. I eventually got in with a neurologist who refused to prescribe the recovery med I knew worked and instead prescribed a med to take at onset. It works when it works, which isn't always. I'm on a waiting list for a second opinion.

For now, take 800 mg of ibuprofen every 4-6 hours to relax the headache's grip. Drink Gatorade or similar to maintain electrolytes. Ice packs may help, or a heating pad.

You have my sympathy.