Thanks mrsJK, I weighed in this morning and as I am only down 2lbs the advice was to try another week, increase my water and perhaps refeed next week. They are concerned about my constant thirst despite loads of water and are reluctant for me to stay on TFR for another two weeks anyway.
If I feel worse in a couple of days I can refeed using the TFR sachets so at least I won't be out of pocket. I'II be doing strictly protein food for the first week anyway and will very slowly reintroduce carbs so should still manage a pound or two a week anyway.
Also, I was told that is it extremely important to sip your 2-3 litres of water a day as if you drink too much in any one time it goes straight through you. Sipping is what hydrates the body, not massive amounts in one go.
Thanks