Migraines from the sun !! Please Help ?

Please help , I have suffered from Migraines pretty much all my life since the age of 7 I am now 26, I have had MRIs done and one doc says nothing is wrong and the other says I have epilepsy..I have never had a seziure that I know of .My sister suffers from epilepsy. I get Migraines almost everyday .The littlest thing will trigger them.Latley I have noticed if I go in the sun for even 5 seconds a full blasted Migraine comes on does not even take 1 minute for it to kick in .What can this be ? As soon as the sun hits me its all over please help I will go see a doc again when my insurance kicks in but until then please give me your opinions Thank you so much.