the condition is called anosmia if you would like to research the many many causes. since your ability to smell has not returned after five years it is likely that it could be permanent. i don't believe that aromatherapy will solve or cure your anosmia.
i gradually lost my sense of smell approx 5 years ago. recent mri is normal. is this condition permanent? . from mri result narrative: "there is mild mucosal thickening of the maxillary and ethmoid sinuses and mild right nasal septal deviation. i can smell eucalyptus in the aroma therapy room at the gym but that's it. nothing else. could spending more time in aroma therapy help?