I've heard of several people with lupus who seem to react to UV light, even if they don't get the rash. Stores with unprotected fluorescent lights (no plastic covers) seem to be the source of many complaints.
As for losing your voice, yes, but in my case it's due to dystonia caused by lupus (it's an extremely rare thing, so I very much doubt that's your case). Since you think it could be Sjogren's, you could try sipping on water and other drinks throughout the day and see if that helps as a starting point.
Hope you find the answers you're looking for.
Neuropsychiatric (aka CNS) Lupus