In my opinion, or at least what I believe, that this "gift" (as Rosemary calls it) is just a sense that every person/being possesses. It is, in reality, a sixth sense, but in certain people it is fine tuned. I think that it's a type of "disorder", not quite that frank, which some people are aware of and others are not.
As blindness, or speech impediments occur in people, so do special 'ups' in senses. Some people 'feel' physically better than others, and phsyically see better as well; the same for this, others can phsyically (and mentally) tune into things.
I'm sorry if my explanations aren't as clear at the moment...it's really early and I stayed up late last night.

But, I have intuitive dreams on occasion, or just feelings. Not quite as strong as you put them, but I am aware of something else that's happening.
(A good example is the Friday that the space ship Columbia broke apart. That morning, around the time it occurred, I was jittery and extremely active, and I
knew something was happening. On the way to school, I just couldn't keep my eyes off of the sky, and I couldn't--wouldn't--sit still. When I got home that evening, and happened to be watching the news--CNN I think--I noticed Columbia, and kind of fell silent for a moment. That usually doesn't happen with me, I don't sit still for casualties. Same goes for 9/11, I felt strange that day as well; actually talked my mom into letting me miss school because I didn't feel right.

)
I don't get headaches though; only times I do is when I don't eat or stay up too late.
All I can tell you is to push some of this aside, and not dwell on it so much, this may be causing an 'overload' in your system.