Good luck to both of you! YOU CAN DO IT
It took me EIGHT WEEKS, honestly, 8 weeks to finally knuckle down to this. I kept having one good week one back week one good week one bad week until before I knew it 2 months had passed and I was at roughly the same weight as when I started, and I'd wasted a lot of money.
So my advice to you is this - IT DOES GET EASIER, trust me! If you can get through the first two weeks, you are doing SO well, and week three will be easier. It is so worth it.
Also, there really isn't any cheating, you get away with practically nothing on this diet, so do your very best to keep it in the rules or you'll just regret the time you've wasted
And lastly, when you're feeling really hungry, I highly recommend trying your products at half strength (i.e. made up with about 400ml-500ml of water). Not only does it help you towards your water allowance, but it will also make you feel like you've had more (especially if you have the two halfs at separate times, then it feels like you're getting an extra product

), and fill you up more.
Day 3 is usually the hardest for me, because I'm feeling very weak and sluggish and desperately want to eat for energy. But this only happens once, after that one day, you will be feeling GREAT, and so long as you don't cheat and knock yourself out of ketosis, you will never have to go through that horrible weak day ever again
GOOD LUCK!!!