This is Dr. David
sore throat can be from acid reflux or from runny nose and allergies.
are you coughing up phlegm or mucus? if you are, you need that cultured.
some lung infections can be resistant to certain antibiotics. a sputum culture and senitivity panel can check for this.
you might need cough medications like guifennesin or codeine.
let me know if you have questions.