Sometimes we find ourselves doing just that. I have been running on empty for several days. Taking inspiration anywhere I can get it. I am sure I am fight a flu bug but I need to rally. Some people ask me why I do not just stay home–I do not always have that luxery. I have a client counting on me and a trial date looming. So even though I am running on empty I am still running.
The clients deserves the best I have to give even when I do not feel like I can. What makes me great at what I do is that when push comes to shove I am still going to keep at.
So when you are running on empty what keeps you going; money, the client, your own determion.

Dawn,
In this business, you “do what you gotta do”. All there is to it. That is why you are successful at it, and in demand. I had a rough few days my self. Not from being sick. Just very tired from some odd hours. Makes you weary, and sometimes makes me a little cranky. Bad times pass, the same way the good ones do. And vice versa.
PS Happy Birthday and feel better.