Howdy,
Been there. Done that. The Tee shirt was eaten by moths.
There are different kinds of "i feel so down and out". First, the normal lowered affect because of losing health, opportunities, abilities, etc. Second, as the literature makes clear, autoimmine diseases can on their own create biochemical depression. Third, the very drugs that we take can cause biochemical depression in some cases. Fourth, if you happen to have allergies, there is another route to biochemical depression.
That's four without even breaking a mental sweat.
It is how we deal with these affect problems that makes the difference.
If the medicos suggest anti-depressants, one should seriously consider them. One also needs emotional support from friends, a group, whatever.
And it really helps if the Lupus goes into remission!

It alos helps to become intereste din other people; e.g. as I have been writing this thinking about you I have less attention to pay to the fact that I feel like *&^%$#@!
Douglas+