Sleeping sickness. I recover from it.

I am 27 years.weight 64 kilo.i am feeling very fatigue when i sit in a chair for a long while.when i sit in a chair or take rest in bed i feel that i am so tired.but while i do my work that time i am very energetic and cannot feel any problem.i sleep 8-10 hours in a day mainly in week days not contiously but taking gap (maintain 6-7 hours in night and 2 hours at after noon) and off days 6-7 hours at night.i maintain a good diet chart.i am not chain smoker(3-5 cig a week) and non alcholic.my problem arise last 7-8 years.no major illness no surgerical process happened in past.so my question is- is there any blood related problem or hormone problem so that i suffer like this.if any blood test needed then suggest me or how can i recover from it.need some suggestion please.