I can relate. I've felt unusually tired for much of this pregnancy but within the last week it's overwhelming. How are you sleeping? I'll fall in deep for a couple hours but for me it's mostly fitful and punctuated with bathroom trips, sleepless stretches and generally sleeping as if I already have a newborn. Which I think is brilliant considering I'm about to have one but it is miserable in the meantime. I remember last I had a baby feeling like I slept better after her birth than the weeks preceding. I say you just go with it and sleep as much as possible.