Hi Ken,
So sorry to hear about the diabetes diagnosis. But the good news is that the symptoms are controllable and it's possible that over time you'll feel much better than you have been for a while. I'm hoping that some of things you thought were mood related were actually caused by the diabetes and the metabolic syndrome that probably preceded it.
I did want to draw your attention to the fact that both sugared sodas and diet sodas disrupt blood sugar metabolism.
For example, here's an article from the New York Times from last February about diet drinks and metabolic syndrome, which is considered the forerunner to diabetes. You probably had metabolic syndrome for a long time before you were diagnosed.
http://www.nytimes.com/2008/02/05/he...on/05symp.html
It says: "the risk of developing metabolic syndrome was 34 percent higher among those who drank one can of diet soda a day compared with those who drank none."
I wish I could get all my friends to stop drinking daily sodas. :(
Anyway, I'm guessing it would help if you could switch from sodas to whole fruits (the more fiber the better) or glasses of fresh water. I wrote about this extensively last year, and a high fiber diet--especially fruit (surprisingly)--helps with blood sugar regulation.
Take care. This may turn out to be good news, since diabetes is controllable.