@Bryonyshcmyony this is the point at which I bring out The Big Stick.
First, as I have reminded you twice now - you are in the weeks 3/4 Doldrums. Little/no weight loss, sometimes an increase, is quite normal for this stage of the WOE. You know it works, because you lost half a stone in the first two weeks!
Second, where is the extra litre of water you should be drinking?
Third, where is the fat? I doubt, very much, that chicken sausages will have much fat in them - plus, unless you made them yourself, they count as processed food - which we're trying to avoid. Ditto tofu. Stir-fries, too, generally tend to use only a little fat - and yours sounds like it was mainly veg which will have been low fat too.
Third - protein. I see you've been adding an egg, which is fine, but tofu is low in protein compared to, say, chicken. And I'd be surprised if there was much protein in your chicken sausages. (Did you check the ingredients and nutritional info on those?)
Fourth - although we allow artificial sweeteners in Bootcamp Light (i.e. from week 3 onwards) it's much better to avoid them, so I'd knock the Diet Coke on the head.
You need to be patient. If you can't cope with daily weighing, and it sounds like you can't, then make your weigh-in once a week. Your body weight will fluctuate quite naturally on a day-to-day basis, even if you're being really strict.