Wake me up before you go go!

Lately I am ALWAYS tired.  I come home from work, and can't seem to make it through the day without a nap.  I can't decide if I am just in need of something to occupy my time, or if something is wrong.  I'd like to think that if I had a full time job, kids, and other responsibilities, that I could step up to the plate and take care of them.  I'm feeling like this isn't the case as of late.  Does anyone know of anything I could do to keep me from being so tired all the time?  Sleeping in is not an option.