From your description it appears you are suffering from Upper respiratory tract infection. White patch on the tongue is generally due to entrapment of dead cells/bacteria/viruses. This could also be due to secondary yeast infection because of the antibiotics.
However you need not worry with the improvement of your cold,flu symptoms and reducing effect of Amoxycillin the patch will go away.
Presently take adequate rest, plenty of warm fluids, do frequent warm saline rinses and maintain good oral hygiene.
Though chances are less, should it last for longer duration pl consult your dentist/physician/skin Spl for further evaluation and management.
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