A lady I work with has had migrain headaches, sensitivity to light and slight nausia for a while. She did a sleep study and was diagnosed with severe sleep apnea. She has been using a CPAP and it's helping her headaches and nausia. Like Funked said, it may be something to look into.
I hope you find out the cause of your problems Gto.
Oh, and Stanford has one of the top sleep study centers around, so at least it's close by.