I just wanted to tell you that YES a headache can last two weeks.
I was motivated to find this forum when I had a headache that lasted 8 days a couple months ago.
I felt like there was something seriously wrong with me. I went to bed with it and even woke up with it (which isn't typical for me).
Then I did some research and found that there are others who have had headaches for that long.
I commonly get tension headahches daily but I did have that horrible constant migraine for 8 days or so recently.
I would definitely suggest you see a doctor so you can start getting on a program to deal with your headaches.
There are several new medications out there and you might just need to get a strong pain reliever/muscle relaxer to knock it out once and for all.
You might have to take a strong dose and go to bed and hopefully you could wake up feeling better....
Let us know how it goes,
the med that my doctor gave me during that long headache was midrin. It has some muscle relaxer and pain med in it and I think it helped because a lot of mine was extreme tension in the forehead that I could not for the life of me release.