Tree, had a big discussion with dh earlier about whether he could make it to the chemists before they close to by some oral rehydration sachets. The end result was - no.
Ds is doing better holding down water than ds2. She is having about 2 ounces every 1-2 hours plus breastfeeds every 3-4. Ds2 hasn't managed to keep so much as a mouthful down all day, but is sleeping peacefully now. Fingers crossed he will be feeling a lot better in the morning.
I feel for you with the non-sleeping dd. Dd went through that for a couple of months and it was living hell. I honestly think my short term memory is gone for good as a result. We are back to letting her sleep in the swing while we watch tv now, just so that I get some child free time. Otherwise I think I'd be dribbling in the corner by now.
I guess consistency is the key. We are planning to start being more consistent with her pre-bed routine as soon as she's better. (The plan was to start as soon as we got back from the festy, but obviously that's all gone pear shaped now.)
We had to go through this with ds2 as well, as he was all over the place with his sleeping after we spent the summer touring the West Coast of Ireland when he was about this age. Its hard work, but the rewards are so worth it. We used to read a story, sing his sleepy songs then put him in his cot and sit next to him quietly and keep laying him back down and giving him a kiss saying, "time to go to sleep now". He used to play, grizzle and try all sorts to keep himself awake, but eventually got the idea and the length of time it took got shorter and shorter. Once he was happy to lie down we started moving the chair across the room until we could just sit in the doorway and eventually just out the door. Whole thing took a couple of months, but he's been really good at going to bed ever since.
Never had the problems with ds2 as he shared with ds1 when he left our room and just sort of copied what he did.
Am dreading doing it all again with dd, but know I have to if things are going to improve round here. I am totally exhausted so it must be a million times worse with you doing night shifts.