Suggest Treatment For Severe Fatigue And Sleepiness

I am always tired and lack the energy to do anything, even basic household chores or exercise! I wake up in the morning tired and can't wait to get back home and sleep, I spend all day in week struggling to stay awake (and I find myself nodding off at my desk!) and even ther thought of going out for a day or on holiday puts me off, because that means getting up early! I sit down when I get home from work and doze on the sofa...it's not children as they're all grown up, it's not too much exercise, I'm too tired to do anything. I cancel plans last minute because I can't muster the energy to get ready and go out. Please help me, this is ruining my life. I'm only 53 and have had a series of upsets and loss over the last 2 years, which I'm still struggling with, my relationship of 2 years ended because I never wanted to be physical or make an effort to do anything...and I'm glad because now I'm on my own I don't have to do anything!