You certainly have quite a history since Covid. I heard that some big university hospitals had to open a special center for those who lost their sense of smell and taste after having Covid. They probably do the same smell retraining that you already had. I'm glad it helped you. It does seem like that shampoo and body wash had something to do too with your health issues plus that antibiotic. Whenever I do any research on taste issues one of the main reasons for it is certain medication, and several antibiotics are listed. I have stopped so many medications that I have been on, just to make sure, but with me that did not help. I have been off of them for months and it was worth trying. Now I'll go back on only the one I really need. They always list the metallic taste when they talk about reactions to medications though, never a salty or sour taste!! Also, once in a while, all of a sudden I have an overwhelming bizarre bitter taste that creeps into my mouth for absolutely no reason at all, usually late in the evening but it passes quickly and I have no idea why but it is scary since I'm always afraid it is not going to go away even though I am wearing my retainer.... Such a baffling disorder. Yes, after going to my dentist, primacy doctor, ENT and rheumatologist and getting no answer I don't think they know how to treat it all all and with my no one knows what is causing it!! So frustrating!!