Hi. Read and understood your history and concerns about your husband who is having headache. He is having sinus infection over months and taken a few cources of antibiotics. I would advise a few things in such a case for proper diagnosis and treatment. - Go for a contrast enhanced CT scan of the sinuses, tests of blood and ENT endoscopy with opinion of an ENT surgeon. A proper diagnosis alone can lead to an effective treatment. Till then continue nasal drops and steam inhalation.