I'm A 71 Year Old Female & Am Having Problems

I'm a 71 year old female & am having problems with total exhaustion. I weigh 140 lbs & am 5'. I am on no medications or supplements. I have slightly elevated blood pressure occasionally. I sleep approx 10 to 11 hrs a nite. I get out of breath walking any distance. I just stay so tired & have started to lose interest in my activities.