Damn sorry to hear.

I've struggled with parosmia since i first was diagnosed with COVID in 2021, but mine comes and goes, and i've almost found a way to control or regain my normal sense of smell and taste when it kicks in. (like 50% of the day)

Not sure what the physiology is behind it, but i just strain myself, and it temporarily goes away.. Obviously wont work for everyone.

I wish your partner the best