constant sore throat day and night

I do chew tobacco but do not believe that is the cause. I sleep every night with two fans directly on me and my mouth open. I do not have a fever or headaches or feel weak. I am 73 years old and have had lung cancer twice with one lobe from each side removed in 1995 and again in 2002. I am an exercise nut and walk or run 2 hours every day but I was diagnosed with Congested Heart Failure in September of 2010. I have since taken Diaretics, Fruthtose and warifin for high blood pressure and blood clots. My average BP is 120/90. I have been tested twice for VD and always negative. I have great balance but have scabs on my face and on my lips which never disappear although Dermatologist have tried everything. Historically I was addicted to alcohol and cigarettes but do neither now. I have normal blood sugar ratings and eat a healthy diet of vegetables, fish and fruits. I eat too much however and now weigh 183 pounds at 5 feet 10. I do have more stress than most people because of financial matters. But I seem to strive on stress and even my dreams are stressful. I sleep 8 hours per day but in 4 intervals.