I'd agree that the first few days are hard, but I think that truly, the hardest part you've already done- accepting the need to lose weight and getting in touch with a CDC. If you're motivated enough to contemplate a tough VLCD, then I'm sure that motivation will get you through the tough first few days.
I agree with Abz- hunger is often confused with thirst- so drink plenty. And if you feel hungry, try having a big glass of water.
If you waver or feel like giving in, pop on here and talk to all the lovely ladies on the hour by hour thread, look through the inspiration pictures, have a nice hot bath, go for a walk or have an early night. There is so much support here, some of these lovely ladies practically carried me through my first week
They always have some great ideas to help you through tough spots.
Hope the appointment went well, and hope to see you posting on here in a weeks time with some great first WI results
Keep picturing a slim you on the beach in a bikini and you'll be fine