Like FireSprite, I don't see it coming until I'm in it. When I (finally) recognize it, I force myself to take a break. A movie with friends, my sister or DS; walking through a favorite antique store; a hike back around Hatcher's Pass and the Little Susitna River; anything to recharge my batteries and to take care of any HALT problems. I've found I can't really focus on taking things step-by-step when I'm dragging around and/or scattered. And really, when I'm overwhelmed, I'm not really seeing the true picture.
Sending (((((hugs)))), my friend! You can get through this!