Me I totally know where you are coming from - I'm nearly 16 weeks and have had morning sickness throughout but it lasts all day and seems worse at night, peaks at about 2/3am. I'm lucky in that I have no other DCs because tiredness makes it worse (so I really really sympathise with you there).
When it was really bad at around 7-9weeks) I found the only thing that helped was forcing myself to eat something every two hours. I lived off little packets of mini cheddars which really helped and if you can get hold of some ginger ale that helped too (ginger beer was too sweet and made me feel worse). There is definitely something to be said for ginger, it does ease the nausea, ginger nuts were great. I think it is different for everyone but plain carbohydrates were all I could really manage, so chips and potatoes or toast were all I really ate at the worst bits and I still have to avoid dairy as it doesn't really agree with the MS.
The main advice I would give is try to have as much rest as you can and as soon as you feel the nausea coming on or getting worse, force yourself to eat something.
Polka I am 30 - and I know that the risk of Downs increases with age and hormones in the bloods also heighten or lower the risk factor. As far as the nuchal measurement is concerned, I asked about it at my scan and was told that 1.8mm taken by itself was considered at the lower end of the risk scale. The midwife said a 2.9mm measurement would be considered at the higher end of the risk scale by way of comparison. Do try and not worry about it too much, I got myself into a bit of a state about the whole thing and I wish now that I hadn't.
Hope all the scans have gone well today!!