I've joined the club of early-risers, which means that between my son waking up to nurse and me not being ablt to get back to sleep after 3AM, I'm EXHAUSTED!!
But for me, the only thing that helps (other than a full-night sleep, which I can't have right now) is MORE exercise. I made myself run to the grocery store this morning for some veggies for lunch instead of drive, and it was about 1.25 miles away. I didn't even think about the fact that they might not be OPEN

so I had to keep going to the next grocery store, another mile up the hill. I walked that portion, though. All in all I ran a mile and walked 3.5 miles, and now I'd never guess that I only got 4 hours of disconnected sleep!
Unfortunately my son is now sleeping in the car in the garage (with the monitor on), so I don't feel comfortable taking a nap myself while he's out there. Bummer.
Anyway, I know what you're feeling, but I feel SO much more human after I've gotten some exercise. I'm trying to do three evenings per week running or gym (usually running because DS doesn't want me to leave him to go to the gym), and so far so good. The weird thing is that I haven't changed my workout routine and I'm not vomiting, but I've lost 5 pounds so far. I think it must just be my sweets aversion---I've cut out all sugar because it sounds gross, and VOILA!!