I've been having the same problem - I find that in addition to all of the above, sometimes it helps to use either a cold or warm pack (or cool damp facewasher or warm damp facewasher) either on the back of my neck or my forehead. Sometimes I end up with cool on my forehead and warm on my neck (or vice versa) and it really does help.

Good luck - these headaches are awful, I hope you get some relief soon!