So tired!

Lily-Anne
I'm tired all of the time, it's becoming so frustrating! 
I was literally falling asleep at the dinner table yesterday evening, and slept for 10 hours last night, yet I am still tired. 
It's been getting worse, it's started around last week when I felt slightly lathargic but it's got to the point I can sleep deeply any time during the day and anywhere! 
Is there anything natural I can do to keep myself awake and not about to doze off?