Hi Amy, welcome and good luck!! My advice is drink plenty of water and keep your main goal in your head!!
We are all in the same boat and if you do get in to a sticky patch, come on here and you will get your support!!
I did it 100% for 6 weeks, had a weekend off and now am back on it 100% for the next 4 weeks. I don't think you can fail at this, it is all dependant on you. Go for it!!