Head Burning Syndrome = SOUNDS like a STD ...not good when you re-read the posts like:
Your mouth is open since you're sucking wind, and your chin strap is too tight, Loosen up that helmet.
Seriously, with the conditions you describe you really should see a doctor before
hammering so hard!!!
.............
I have had the exact same experience when I started riding harder/longer than I was used to doing.
...............