Hi Sore throats but I take antibiotic But still

What are the causes of your medical condition ? 
1. Lack of drinking fluids
2. Mouth and throat infections
3. Inflammation of the salivary glands
4. some medications side effects
5. Sinus infections
What to do next?
1. consult  ENT doctor 
2. Drink plenty of water
3. Make sure not to take a medication causes dry mouth as a side effect
4. Treat nasal sinus infection and inflammation and avoid breathing from the mouth by using medication like such as cortisone sprays and antihistamines orally 
5. Treat mouth and throat infections with antibiotics such as amoxicillin
What are the necessary tests:
1. Clinical examination by the specialist doctor
2. Examination of a sample of saliva