Work in busy environment - regular headaches

Hi,
I'm 12 weeks pregnant and am having a really hard time at work. I work in a state government call centre which is very busy and i'm on a computer constantly.
I constantly have headaches since falling pregnant and atleast twice a week get very bad migraines.
My doctor has given me a low amine diet to follow but it doesn't seem to do much.
It's very early on in my pregnancy, and we do need the money i bring home, but these headaches and migraines are driving me insane. Would this be doing harm to my baby? Should i finish work early because of this? I'm just starting to find it very difficult, and it seems to be getting worse as time goes by rather than better.
Thanks for any help or suggestions. This is my first pregnancy so i really don't have any idea what to expect.

just as a general rule for headaches...
drink lots of water...you will need more because you are in an airconditioned environmet AND cos you are pg
ask your boss for a screen sheild (cant remember their actual name) but threy sit over your screen and take away the glare, cheap as too
take regular breaks

And I would get my eyes tested. A lot of headaches can be caused by eye strain, so if I start gettigng headaches for no reason I always go and check my script.

HTH...and GL with the pregnancy! :)