I'm kinda a broken record on this in the fasting thread along with Dago and MadMarsha, but people should try fasting. Autophagy has some amazing results in helping heal sense of smell.
It's the main reason that I got back on the fasting train. Willing to try anything. I want my peanut butter back! Also, realized last night that my tooth paste and chap stick now smell weird. I no longer smell minty things correctly, either.