Hi Thaper,
If you have stuck to plan, then you should already be in ketosis, it usually kicks in around day 3 or 4. I felt crummy for about 3 days, really bad headaches which I would wake up with and couldn't get rid of, and cold and tired all the time. The headaches were probably due to carb withdrawal and the other symptoms all part of going into ketosis.
Stick with the plan - I had my first official weigh-in after 10 days and somehow or other I managed to lose 17lbs!!! At my week 3 weigh-in I had lost 26lbs, so only 2lbs to go to the 2 stone mark.
Can you text or call your counsellor and let him/her know you are struggling? I am sure they will have lots of words of support for you.
If not, take a look through the threads here, the people are lovely and very supportive.
C x