I too have a dreadful time getting to sleep once in bed. I have gone off though as you say at the most inappropriate times. I have listed a few things for you to try regarding your night and bed time sleep. You have most probably tried them, but maybe there might be one or two that you haven't tried.
Take a warm bath - with some lavender or chamomile oil in
Get a massage - a very gentle one though. The best one I find is a very gentle scalp masssage
Listen to music - or even your favourite sounds i.e. dolphins, rippling streams, anything that you find relaxes you
Drink warm milk - with honey if you like it
Drink herbal tea - a popular one is chamomile
Eat a bedtime snack - by this I mean something very light, never go to bed hungry
Avoid caffeine, alcohol and tobacco
Sleep in a well-ventilated room - no draughts, not too warm and not too cold
Sleep on a good firm bed - never an orthopaedic mattress if you have a bad or painful back
Sleep on your back - if possible
Get some physical exercise during the day - I know it's hard at times, but even gentle stretching or sitting down mini-workouts are good
Keep regular bedtime hours - not always easy I know, but try your best
If you can't sleep - get up and maybe do a little gentle tidying up or something like that
Don't sleep in - do your best to get up soon after you have woken up
Try to get up a bit earlier in the morning
Keep your bed as a place for sleep - try not reading anything that will require intense concentration. Don't do crosswords or any type of puzzle and definitely no work from the office
These are just a few things I have tried in the past. The thing is that when you do nod off, don't worry it is only your body giving the signal that you need to rest, which is an obvious thing to say I know, but when we have lupus it is most important that we have these little rests and nod-offs. Of course the other alternative is to get sleep medications, but I personally don't want to go there.
Hope the above is of interest.