Recently, everytime i speak even shoftly, i start coughing because of no reason and i also feel something strange on my troath. what could it be?

Throat irritation: If you are not an asthmatic, it is likely that the back of your throat has been irritated : by bacteria(strep or others), viruses, swallowing something abrasive, or perhaps severe gastroesophageal reflux causing throat irritation from stomach acid. Explore the possibilities with a doctor to get at how to treat the appropriate cause...