You might want to check the following websites daily. I don't think it's coincidence at all. The sun and earth go through seasonal changes throughout the year, so perhaps your body is sensitive to these changes? The last two websites are ones that can be searched backwards in time, too. If you check them daily, you might see a pattern...I know auroras pick up in the fall, so the sun does have its seasons.
Space Weather Now:
http://www.swpc.noaa.gov/SWN/index.html
*Check the Magnetic Field Component (is it North, South, or Neutral?), Solar Wind Speed, and Dynamic Pressure.
*Pay special attention to days when the Dynamic Pressure Drops to zero, especially when it's zero and neutral for a long period of time.
Todays Space Weather:
http://www.swpc.noaa.gov/today2.html
*Read the 3-day Solar-Geophysical Forecasts.
*Check the Solar X-ray Flux graph for an increase in strong solar flares, especially M-class and X-ray class flares.
*Check the Satellite Environment Plot's 'Estimated Kp' graph for red and yellow bars (which indicate geomagnetic storms underway and an unsettled geomagnetic field).
*Check the Proton Flux and Electron Flux graphs. Pay special attention to days when the blue line in the Electron Flux graph goes 'crazy jaggedy' or when any of the lines in the Electron Flux graph start to dip or 'zig-zag' on you.
Space Weather Archives (Click on 'Currently in Effect):
http://www.swpc.noaa.gov/alerts/archive.html#2006
*This one is pretty self-explanatory - check for X-ray and radio events, proton events, electron fluxes, sudden impulses, geomagnetic K and A storms, stratwarms.
*This website can be searched backwards and then compared to your 'seizure diary'.
Space Weather - Sunspot Page:
http://spaceweather.com/
*Check for sunspots and coronal holes. Also, solar wind speed and density.
*This website can also be searched backwards and then compared to your 'seizure diary'.