Hello...
This may be due to a viral/bacterial infection or due to the poor AQI leading to allergic reaction.
Wear a mask and change regularly while going outdoors.
Next Steps
plane steam inhalation.
vit C supplements.
healthy diet
good hydration
can use tab montec LC one tab after dinner for 7 to 10 days.
solspre nasal spray once before bed
Health Tips
if symptoms doesn't improve/relieve please see a doctor in person for a proper physical checkup.