Hello,
According to me you need to start steroidal nasal sprays and gargles to avoid this post nasal drip.
Long term post nasal drip will lead to recurrent throat infection.
Better to start the medication and get rid of this.
Normal tendency of nose to produce the mucus which will tend to drip posteriorly into the throat causing post nasal drip.
Instead of taking multiple antibiotics to treat throat infection better to treat post nasal drip and get a better solution.
Next Steps
Visit nearby ENT if possible for Diagnostic Nasal endoscopy.
Health Tips
Start steroidal nasal spray and medication.
Gargles with lukewarm water 5-7 times a day.