Back in 1998 when I was DX with lupus it was the profound fatigue that lead to tests which eventually led to lupus. I was treated for depression as well but much like you my mood increased but the fatigue level remained severe. I also have thyroid issues which can cause mood changed, severe fatigue, joint pain etc...

If I were you I would bring it up once more with the doc and see what she says. It might be depression rearing it's ugly head once more but it also could be something physical like in my case.

I wish you all the best and am sending you as much energy as I can muster. *hugs*