Dear J.,
First, I suggest that you check your blood pressure. High BP can cause bad headaches. If that's the problem, and your BP is incredibly high, go straight to an emergency room, so they get it down. Assuming that's not the problem, in addition to over the counter headache meds, you might try my "headache torture treatment", as my husband calls it. Lay down with your feet up and cover yourself with a blanket to keep your body warm. Put a heating pad (set on low) behind your neck and a chill pack (or a package of frozen peas) on your forehead and over your eyes. If you can't stand to do both at the same time (the hot and cold), just do the cold. Now for the good part--pretend you are on a tropical island. The warm sun is shining on your body, but your head is under a palm tree (warm body, cool head). Try to relax.
I also suggest Excedrin Migraine. I think it's the best OTC headache med. One word of advice--it has tons of caffeine in it, so take it early in the day, not late.
I hope this helps, at least temporarily, until you can talk to your doctor.
The "Headache Queen",
Deb D