Valdeeves - sugar is carbohydrate though! It's the level of carbs that you eat that will keep you in ketosis.
coldethyl - that's not good if you're fainting/cramping, and suggests that something is seriously wrong with what you're eating. By now, you should be used to drinking the amount of water, and 2.4 litres is not that excessive.
The first thing I would say would be salt - do you cook with it? Do you add it to your food?
Second, are you eating enough? It's a common problem - everyone associates dieting with teeny tiny portions, which isn't necessary on this WOE.
What about the electrolytes? As well as sodium, you should be eating sufficient foods to get enough potassium and magnesium. Like you, I prefer to get what I need from food - things like salmon, avocado and spinach are all good sources of these.
If you have been suffering, though, as a short term measure I would DEFINITELY suggest that you look at supplementation, to get you back to normal
Are you eating enough fat? You say you've been pushing your veggies up at the expense of meat - this could also mean that you aren't eating enough fat.
You don't have to buy expensive cuts of meat - shin of beef, breast of lamb, chicken thighs, pork belly are all relatively inexpensive, and higher in fat.
And lastly, list out for me what you have both been eating over the last week or so, please - so we can see if there's anything else.
This is not a WOE that should cause you any problems, but (like any other) it has to be done correctly.