Sorry you're still suffering from headaches babe. Sounds like you're drinking enough, are you sleeping well? And do you have thin curtains (random I know, but I used to get headaches staying at my inlaws because the room I slept in had thin, yellow curtains that really glared the sun in and would give me the most unpleasent headaches.)
Maybe best to get it checked out though, especially as you've had it a while.
Hope things are going well at work!
Bron