I've been having headaches for a month or so and was wondering what the cause could be?

Headaches won't stop: Headaches can be caused by simple and serious things. I would advise you to seek medical attention urgently. But, this could as easily be reactions to the environment, food, sleep disturbance, sinus infection, dehydration, or a reaction to too many headache medications. A good health care provider should be able to help you sort through the various possibilities and get you headed to health.