Thanks for your tip/reply. My sense of taste/smell is much better now and seems to be on a good trajectory as well, I won't seek more treatment at the moment. What you describe kind of sounds related to a stellate ganglion block[0] which can have these instant (and for some permanent) effects on covid-induced anosmia.
[0] https://www.nbcnews.com/health/health-news/long-covid-lost-t...