Yeah, this is familiar. I hit that wall once and basically half passed out - total dehydration and not enough food. I had worked out like a fiend that day, then went on a long ride with not much more than a small amount of water, juice, an apple and a power bar in me. By the time the late afternoon rolled around, I guess my body had pretty much had enough.

And stress is a killer, as my doc keeps telling me. I'm just starting to take up yoga (ouch! but good ouch), to help offset the stress at work that I can't control. Take care of yourself.