Just for a shot in the dark here (as a physical therapist who runs a headache program), headaches are often made chronic by TMJ (jaw) compression. Headache often causes an increase in jaw tension which compresses jaw joint (the most sensitive joint in the body, since it assists in sensation of horizontal and contributes to balance control). A mild increase in stress at TMJ is a very common cause of headaches (plus tinnitus, vertigo, sinus symptoms). One of the most effective methods of treating TMJ compression is to 1. place tip of tongue at roof of mouth about half-way back from teeth; 2. keep tip lightly pressed here as you open mouth about 2/3 of full open (not all the way) for about two seconds, 3. then close for two seconds, repeat 10x. This inhibits and quiets jaw muscles and unloads the TMJ structures. This is often very effective. Additionally, one should invest lots of attention to correcting their resting jaw posture... which is to keep the tongue flat against roof, teeth NOT touching, lips together, breathe through nose, while holding head tall upright (not slouched) (jaw is actually part of the neck and round-shoulders posture is common cause of TMJ). This is the normal posture of the jaw, although many people do not realize this since their posture has been abnormal for so long.