Thing is Mia Prawns can be quite salty, as were the peanuts you had last week too. I'm not casting up, honestly, but this is one of those diets where nibbling on foods that aren't quite right can really have a knock on effect.
Why not try SS+ for nibbling legitimately on Chicken Lettuce etc?
You seem to be so stressed with this, and pre weigh ins I've noticed you tend to panic about water or what you've nibbled on. Why not cut yourself a bit of leeway and have something legitimate thats not going to have the water retention/carbs or calorie/fat issues?
And your losses are not rubbish, you are actually "bang on" for the standard weight loss on CD. I think thats great!