hello and welcome to HCM,
Since you developed a reaction to the antibiotic, the doctor would have told you to stop the same as it would have been harmful to continue the same. But since your infection has not improved and in fact has worsened you need to immediately see a doctor and take a course of another antibiotic which is safe for you.
For immediate alleviation of symptoms you may need to also take an injection after test dose.
Avoid anything cold
and spicy and do lots of salt water gargle
Take only warm fluids
If even after a complete course of antibiotic and anti inflammatory your symptoms persists then you may need to get some blood test
and also think about an Upper GI endoscopy
take care and get well soon
Dr Sriram Nathan