Hi Lion,
Wow. i could've written your post myself, right down to the yawning thing! i just went to my rheumie this morning because i have been having a mild flare, but i'm also having the exact breathing problems you describe. i've had this periodically ever since i was diagnosed w/SLE back in 2002, but it comes and goes and this time it seems to be worse.
during this flare i've been having the awful mouth and nose lesions, painful skin, some joint aches, fatigue, costochondritis, the occasional stabbing pain when i breathe, and some sore spots. this time its been about 3 weeks so far.
my doc did all the bloodwork etc, and then also sent me for a chest xray and gave me a referral to a pulmonologist to have the pulmonary function tests done. he said it could be something not related to lupus, such as a virus. or it could be lupus-related -- pleurisy, pleuritis, or something called "shrinking lung syndrome". i looked it up and found a little info, but not too much.
i hope you feel better soon, lion, and please let us know what you find out!
Larissa