hi there, your husband may be suffering from the common cold
or could be infected with other bacterial infection on which amoxycillin
is not working. Usually common cold is self limiting and subsides by 5-7 days. Let him continue the course of amox and let him take a lot of rest along with warm saline gargles, some analgesics like diclofenac
sodium and hot ginger and camomile tea. He should be better in a weeks time, if not then you can get a throat swab culture done and according to organism grown and its sestivity a fresh course of antibiotics can be given. Let your local GP guide you for the same. Also moniter his blood sugar so that they are under control. Take care.