Is AF turning into chronic fatigue? What is the difference?

Hi, I am just wondering the difference between AF and Chronic Fatigue. The last few days I have started feeling very fatigued and stiffness and pain in my lower back that is very uncomfortable. Also I know that they say in Chronic Fatigue you have a sore throat which I have had a tight sore throat on and off for about two months. So I am scared that I am slipping or have already slipped into CF. Any information on this subject would be helpful.

thanks!!