When I was first injured, horrible horrible headaches were one of my worst symptoms. If you can't get ANY medication, here are some other things you can try:
1) Put your feet in hot water - VERY hot, as hot as you can stand. Put ice packs on your neck and forehead. Sit in a quiet, dark room.
2) Avoid triggers such as TV, computer, reading, loud noises (this meant I spent about 6 months lying quietly in my darkened bedroom).
3) Take max dose of tylenol and max dose of aspirin together. This is the "home-brew" migraine cocktail.
As far as medical treatment goes, these are the things that ultimately helped my headaches the most:
1) vision therapy - find an eye doctor from
http://www.braininjuries.org or
http://www.nora.cc who can do a vision efficiency evaluation. THIS IS NOT THE SAME AS A REGULAR MEDICAL EYE EXAM.
2) headache preventives - the two that worked for me were elavil (though it got less effective over time) and topamax (this is working great for me now)
Hope you can get some relief soon. I know it is SO SO miserable.