Hi, Severe headaches could have primary or secondary causes. Headache not been alleviated by rest would be most likely due to something else rather than over work or hangover. Associated symptoms like loss of apetite, persistent tiredness and non response to Ibro could warrant a more detailed evaluation. Considering the fact she is not eating, taking Ibro which is a non steroidal anti inflammatory drug could cause gastric irratation, gastro intestinal bleeding and at times perforations. Knowing whether she has fever, abdominal pain, her age and recent sexual activities could be useful in orienting the diagnosis. Also, her past medical history, emotional history, history of any migraines with her or the family, psychological state and risk factors for depression could be very instrumental in formulating an appropriate working diagnosis. Seeing a physician for a proper medical consultation is my advice. Hope this helps, Luchuo, MD.