Have you noticed that you have increased the amount of pork you eat? I used to have a sensitivity to pork, I threw up though. So I just didn't eat it. After a long time (10 or so years) I decided to try it again and I was fine. I had a similar allergy to tomatoes. Every time I ate tomatoes I got a headache the day after. I cut tomatoes out of my diet for 3 months, and now I can eat them just fine.
I get migraines though, and I find that there are a lot of foods that will trigger my headaches. Once I recognize the trigger I will cut it out of my diet, and then slowly re-introduce it when I feel appropriate (usually > 3 months).
Also, when I get migraine headaches, I get a huge amount of pain behind my eyes. Sometimes one eye, sometimes both. I also sometimes get intense pain at the top of my spine/base of my skull (this is where the part of the brain that operates the eyes are located - ocipital lobe).
I hope I have helped. http://www.healthboards.com/ubb/jester.gif