For those of you with headaches, stock cube dissolved in hot water, bovril or marmite in hot water will sort it :) Also add more salt to your next meal. Headaches this early on are usually caused by electrolyte imbalances so upping salt can really help :)
Failing that, you're probably in sugar withdrawal. Not going to lie, this absolutely sucks but it's like any withdrawal, it passes. Your body needs to break its relience on sugar and as long as you dont give in and carb binge, it will be gone in about 18 hours from when you get your first headache.
Remember how shit you feel now and will feel on day 4, nothing motivates you to stay on track more than knowing you'll have to go through this again if you fall into carby twatdom.
I was 18st 5lbs when I went through what you're going through now and ended up with full on flu like symptoms from day 4 until day 10. I'm talking runny nose, sweats, body aches, banging headache and even, wierdly, loss of appitite
. I also slept for 5 hours in 48 because I was wired. You don't get to 18st 5lbs (I was 19st 1 in Jan) without having some serious relience on sugar, so my sugar withdrawal was intense. Worked out since then I used to consume anywhere from 100g - 150g sugar PER DAY including fruit and in total around 300g-500g of carbs. My diet was totally acceptable in weight watchers, it's not like I was stuffing my face with takeaway every night or anything.
So, from that to under 25g carb per day is a massive, massive shift and i went cold turkey, so you can imagine the shock to my system.
Some of you will have been consuming similar amounts to me so give your body a break, this week it's going to have to learn a whole new way to function!