An Absence of Creative Motivation: Solutions?

I suspect I'm not the only one who goes through this, so let's have a group discussion.

There are times when I am so creatively motivated that I can barely choose the idea I want to work on. I'm firing with ideas and momentum and I spend almost every waking moment on what I refer to generally as "projects." Whether this is writing, web design, photography, or something else, I am fired up and motivated to make.

At the other end of the spectrum are times like today, where I feel creatively exhausted. It's like hunger pangs of the soul or something-- I can't quite describe the sensation, but my brain is drawing down into my inner fuel tank for motivation and energy, and it's coming up empty. I had intended all weekend to try and get some writing done, but it never happened. I've got the desire to create, but seem to be lacking motivational energy.

Where does this energy come from? Is it like physical energy, fed by food and sleep? Or does it have its own unique kind of food? Am I not "eating" right for my creativity? I will admit that I have been reading rarely if ever, over the last few months. And I've been under a lot of stress, trying to find a new job and with yet another cherished family member passing away. I'm trying not to be hard on myself, and one thing I have to remind me is that creative, fun projects are still work like any other work, and I still need downtime too. But I'd like to find a way to keep my creative tank full, or at least more full.

Ideas? Thoughts?