I agree with feralkittymom that it doesn't sound so much like depression as it does a kind of persistent dissatisfaction with life. For what it's worth, I think the research says that antidepressants aren't all that effective for mild depression. Therapy tends to trump meds under those circumstances.

If you've got chronic pain, though, I wouldn't rule out the effect of that on your mood and your felt capacity to engage with others and in life. I would think that the effort of fighting through the pain would take a great deal of energy, leaving you somewhat depleted emotionally and otherwise.