You know Jill... I recently got so tired myself. (Not pregnancy tired) I had some lab work done and turned out I was anemic. My iron was 9.3. I started taking some yucky iron pills, but even after a few days I am starting to perk up. Careful with that one though. Best to get a lab done if you think your iron is low. You can get too much iron and it can make you sick.
The other thing too is that maybe you are just tired. Tired of people... tired of dealing... Tired of life in general. That can be physically draining when you have a lot on your plate. If I lived closer I would
SO take you out for a relaxing pedi, mani and a stiff drink.

Tired problem resolved.
I really do hope you feel better soon though.