...Why did I not remember that I've been diagnosed as anaemic in the past and was prescribed iron by my GP a few years ago?
After months of low-level constant 'blah' and incessant hankering after naps, it occurred to me in a dream (I kid you not!) that it could be low iron behind the lethargy again.
Not only do I have history of anaemia (d'oh), I also have very heavy periods due to cooper coil (which is otherwise great).
Rather than wait for a doctor's appointment, I got myself a couple of different types of OTC iron tablets and have alternated them on a daily basis for nearly two weeks - and shock, gasp - I feel fantastic again! Sigh... so I'm posting this as a PSA, just in case anyone else is in the same boat.
:)