I have been taking Cephalexin for almost a week. I had sinus surgery. The headaches were the worst. Now 5 days later I can hardly swallor water. Had the stints taken out of my nose yesterday and the dr. said I had "Thrush." My mouth is full of tiny white sores. Gave me difliucan a one pill kills all. One d;a;y later I am still in pain.