Hi. I had a look at your MRI image. It shows nasal polyposis. The turbinate enlargement and polypoid tissue in your nasal cavity reduces the airway circulation into your sinuses thereby precipitating collection of mucus within the sinus which gets infected(sinusitis). In your MRI, the whitish hyperintensity in the maxillary sinus on both sides is indicative of infective material and explains why you have headaches. Aslo, the blockage of air currents created by the polyp and the enlarged turbinates and inflammation, reduce the air reaching the roof of your nose causing alteration in smelling capabilities. What you need is a CT scan followed by endoscopic sinus surgery for removal of your polyp and widening of the sinus opening. Following the surgery you will need nasal sprays and medications for many months to prevent the reoccurrence of the polyp. Please do share the CT scan as well. MRI does not give a good sense of the bony landmarks that are important before surgery. Let me know if you have any further questions