I'm persevering. Made it into work today, but there's a 16 hour day ahead of me and this is by far the worst cold/ fluey symptoms I've ever had. Stopped at Tesco and picked up some Kalms and some lemsip. At this point I don't know or care if there's carbs in the lemsip, I need the medicine so it's fine.
I'm on day 6 now so nearly through my first week (yay) and I haven't yet cheated at all. If I'd still been on WW at this point and I'd fallen ill, I'd have binged every day until I was feeling better. We're talking a full pizza to myself per night for a week most likely. In contrast, I've stopped craving completely and the last thing I want to do is make myself feel worse by eating a ton of carbs.
I actually don't think this is carb flu, I think I've picked up a bug at the worst possible time! So I've in effect got a bad cold, and on top of that I'm going through carb withdrawal at the same time... lovely! 
The sleeping thing though I think is carb related unfortunately. I think my entire life, I've relied on low blood sugar after a big evening meal to make me sleepy, and that's sent me off to sleep with no problems. I don't have the blood sugar crash anymore so in effect, I'm not experiencing tiredness so there's nothing to "cue" my body into wanting sleep. The lack of tiredness combined with my cold is knocking me for six.
However, the very very very last thing I want to do right now is binge on carbs and put myself back into glycolysis, then have to go through this all over again so at the moment, my will power is holding out!