Could also be the stopping smoking. When I quit 20 years ago I lost my sense of smell until I had nasal surgery to remove the accumulated polyps. I think the smoke was keeping them in check, but that's only a theory and certainly does not make me want to start smoking again.
Without a sense of smell all you can taste is sweet, sour, salty, bitter and umami. It's weird, too, because you can develop a skill to differentiate between types of sugars, but you can't tell for example the type of fruit, only that it is from fructose.
Of course your issue could be the meds. I just thought I'd throw that out there.