I don't suffer from the same thing, but I know a constant headache would really wear me down.

As a non drug treatment you could try acupuncture. I got great relief from sciatic pain just recently from a short course, and a GF has weekly acupuncture as a deterrent/ treatment for migraines.

Aromatherapy is another option that many people find successful in the treatment of headaches. Use of the correct oils can help increase relaxation and decrease stress.