What Causes Shortness Of Breath And Excessive Sweating?

I get out of breath just walking 50 feet from end of house to laundry room, sweat heavily while cooking, doing dishes or walking in store. I also get shortness of breath lifting hands over head, making bed. I am over weight. I have this condition for at least 5 years. My physician has sent me for chest xrays, and stress tests with a cardiologist. His diagnosis is I need to recondition myself. Due to the sweating and breathlessness, I avoid many activities with family and friends and can t look for a part-time job until I get these problems under control. Any idea of what else could be wrong.