Aww I feel for you, hilang rasa macam ni memang nagging kan A few of my mum friends went through this after bad colds and it took anywhere from few days to 2-3 weeks baru balik normal, so don't worry you're not alone! Since you've tested negative for Covid and flu, it's likely post-viral loss of taste and smell je, but I'd suggest you check in with your doctor just to be sure and maybe they can give you something to speed up recovery. In the meantime try strong flavours like ginger, garlic, spices, at least you'll get the sensation even if rasa tak kena yet, and make sure you're eating enough to keep your energy up sebab body ni kena recover from the infection. Hang in there, sis!