Re: been suffering for awhile
I'd recommend talking to your doctor, and maybe having an appointment with a neurologist (first appointment, tests, followup). An EEG (strobe test) would be the test that COULD help see if you have a form of epilepsy or not.
Speaking in generalities, it SOUNDS like it could be "photo-sensitive" epilepsy, or where flashing lights (light through leaves) even the screens on windows in some cases can cause the symptoms.
IF this ends up being the verdict, also watch out for Florescent lighting (long tubes especially) due to their "cycle rate", and "tube monitors" (not flat screen) also have a "refresh rate" that bothers some of the photosensitive patients. You should know already if some computer displays/TV's cause symptoms with you.
Hope that little bit helps.