sounds like you might also have allergies? Riding the bike, coming back feeling ichy. Benedryl or better yet, its generic allergy medicine will stop that drainage that is making your throat so sore. Better yet, it will help you sleep! I agree with other post that it sounds like sinus drip down the back of throat. You wouldnt actually notice it, its not all thick like a cold. You could have never had allergies your hole life and have them now. And they can make you miserable. Feel like the flu sometimes
oh and Honey mixed straight up with some lemon juice always makes my throat feel better in a pinch. a couple teaspoons of honey with lemon...(ok ok its a couple tablespoons! hah)