I Got The What People Around Here (Memphis, TN.) Called

I got the what people around here (Memphis, TN.) called the "Memphis Bug" in early October 2015. It acts like the flu, but you have no fever. A few days before Christmas I got better. Just after Christmas I got the flu. Didn't think much about it. Still have it, but the cough is not as bad. Feet stay cold all the time. Have a sciatic nerve problem that causes me lots of pain walking more than 50 feet. October 2015 I weighed 260lbs I checked last week and I weigh 221lbs now. No high blood pressure. What could it be that is still causing me to be ill?