There are so many causes for bad headaches/migraines. I know how miserable they are - and I certainly don't blame you for wanting to get some relief.
Cayenne is many times very beneficial (you can take the tincture since it will absorb into the bloodstream long before it gets to ileocecal valve).
Caffeine can also knock out a headache/migraine...and if you feel you can handle the 'stimulant effect', you can try a cup or two of coffee or strong black tea.
are very good for relieving pain (and constipation...which can also cause migraines/headaches). So either a Coffee-Enema
or just a warm water enema
may be beneficial.
If I had to go with an OTC, I'd go with plain aspirin as my first choice. Some say you shouldn't mix cayenne with aspirin. There's an animal (rat) study that shows that cayenne reduces the bioavailability of salicylate...and enough cayenne can even eliminate all trace of aspirin. Rats aren't people...but this study http://www.ncbi.nlm.nih.gov/pubmed/10537230
may give us some clues as to how cayenne stops bleeding. I'm not suggesting you 'mix them together'...but I wouldn't personally worry about having a few squirts of cayenne tincture, and if that didn't work, then taking an aspirin or two a couple of hours later.
My first "go to" would be 3-4 squirts of cayenne tincture (or Brain Formula, which has Gingko, Cayenne and Kola nut...so it has some caffeine), and then a CE.
'Hope it's gone already, and if not...'hope it eases up soon!