Theta,
After reading your last couple of posts here, it sounds as if it's about more than the tears. I wonder if you've talked about the Lithium with anyone else who is taking it. Compare notes. Perhaps the dose is a little too high for you right now.
I also just read where you are now situated. If you've moved recently and are not happy where you live, that's a big thing and enough to make a person feel different, especially if you've been through a cold, dark winter.
e.g.
Seasonal Affective Disorder