I'm not all that knowledgeable about the different ways lupus can affect a person but according to the lupus.org website, lupus can cause cognitive dysfunction (confusion, fatigue, memory impairment and difficulty expressing thoughts).
It also says:
So it sounds like you may not necessarily have to have a lesion on your brain to experiencing these symptoms. I don't know about treatments specifically for lupus patients but I know in general for people who are having memory problems they try to write all the tasks they need to get done down in an organizer that they consult with constantly.The reasons for these symptoms are not known. It may have something to do with changes in how a group of chemicals known as cytokines are handled or may be related to certain parts of the brain not getting enough oxygen.
Other tests including:
brain wave tests (EEG),
magnetic resonance imaging (MRI) or
computerized tomography (CT) scans of the brain may all be normal.
Cognitive dysfunction may come and go on its own, so the management of cognitive dysfunction is often frustrating and currently no optimal therapy is available.
Antimalarials and/or steroids may be useful.
Counseling, cognitive behavioral therapy and other interventions that assist a person in developing coping skills may be helpful.
Regarding your family situation...I currently live in LA and I know what you mean about hating it here (it can be so stressful with the traffic and everything) but on the other hand having a strong support group of family and friends is so important with a disease like lupus. Especially with the cognitive symptoms you're experiencing, moving back to CA may be an option you really need to consider.
Hope that helps somehow and didn't sound too advice-y. I'm sure that whatever you decide to do will be the best decision for you =)