I Have A Reoccurring Sore Throat, With Thick Post Nasal

I have a reoccurring sore throat, with thick post nasal drip. I never start off congested, I just get a lot of mucus in my throat. My ears get itchy as well. Thinking it's allergies, I took Benadryl but I feel a little tightness on the right side of my throat, and no relief of the sore throat. Why do I feel this tightness and could this be something more than allergies?