My mouth and throat feel like sandpaper. i don't smoke. what's causing this?

Dry Mouth: Are you a mouth breather? When there are enlarged tonsils, nasal blockage, allergies, mouth breathing happens. Make sure you have an habit of drinking a lot of fluid, i mean water mainly. If not comfortable, see your doctor.

Could be: Post nasal drainage from allergies. Symptoms would typically be worse during a certain season unless you have allergies to something indoors, like dust, mold, etc. Could be acid reflux. Usually associated with frequent throat clearing and the sensation that there is something stuck in your throat. You may or may not have heartburn though.