Hey Daisy
As you can see, you are not alone!!
I, too, had a bad headache and felt achey and weird the first few days. At first, I was thinking- this cannot be good, what kind of diet puts you through this pain? But Clovey's advice really helped me- your body really is going through withdrawl. And you WILL feel, look, and BE better because of it.
I gave up caffiene once (yeah, I'm back on, so the story does lose SOME of its impact
) I even did it gradually, but let me tell you, that's a crappy feeling. But once I got past it- WOW! I never felt better, slept better, or had better energy. I think of this diet and regaining control over sugar and carbs similarly. I'm only just beginning Phase 2, but I can already tell that my energy levels are on a more even keel.
Also, those first few days, I just don't think I was eating enough. So I upped my portions a bit- or really just gave myself permission to eat a bit more. I don't think I ended up eating all that much more, but I just had to take the pressure off of eating itty-bitty portions. So EAT! Don't be hungry.
You CAN do it!