Why I do I still have pain in my sinuses 5 weeks after FESS surgery?

After suffering from chronic sinusitis I had FESS surgery. The doctor said all 4 sinuses were diseased, they opened up all the sinuses and removed some polyps. I started to feel better 2.5 weeks after but then came down with an infection. I was given a weeks worth of antibiotics and a steroid nose spray. 2 weeks later I still have loads of pain in my sinuses no discard, just pain. Could it just be that my sinuses are still healing? I have also had pressure in my ears. Thanks.