Hi Wendy: I agree with Angelhair, it could be generalized anxiety. If that is all that is going on, I would agree that you might want to talk with your physician about an antidepressant (or a mood stabilizer of some kind) as well. Anxiety can be caused by rumination, that is, worried thinking that can be managed by antidepressants.
Two other things come to mind, however; when was the last time you had a complete physical? It might be worth going in for one, to rule out something that might be causing it.
The second thing, is that once the physical component is taken care of, you should honestly consider seeing a professional who specializes in anxiety/depression issues. Someone with Cognitive Behavioral Therapy expertise can help you change your life. Even if you get a prescription for medication, unless you change how you are living, and how you view your problems, the symptoms are only being "covered up" by the meds and are likely to return if you stop taking them.
I hope this helps!