What can i do about my head hurting all the time?

i keep getting plagued with head aches and sinus pressure. i went to the doctor and she told me that it may be a sinus infection and gave me anti bio tics and flonaze but that doe not help. i also have been neti potting in case it may be allergies but my head still hurts and i feel sinus pressure, pain and like the left side of my sinus is blocked. i dont know if it is the weather cause it has been cold for half the year, i have tried taking pain relief to make the pain stop but it does not help. i taken aleve, ib pro fen, Excedrin extra strength, acetaminophen, aspirin, and even the migraine pills they sell at Walgreen's. but they barely help. i tried taking the store brand sinus pain relief but all it was was acetaminophen and a decongestant. i really dont know why this keeps happening or what i can take to stop the pain.