When I came off of gluten five years ago, nobody warned me that I would feel like crap for a few days, but I could tell it was clearly withdrawal, and although I was tempted to eat something carby and sugary to feel better, I knew it would just prolong the process and I'd have to start all over. I suffered through and am so glad I did. The withdrawal symptoms only lasted about a week and included fatigue, irritability, upset stomach, nausea, diarrhea and a monstrous headache (if you take something for the headache, take Aleve rather than Advil -- Advil is not always GF. Aspirin is also GF but may upset your stomach even more). I didn't go totally carb-free, so that helped a little with my energy level. Rice and potatoes are naturally gluten-free, so I included both in that first week meal plan.
Side note: if you want to feel really great, you should consider going totally grain-free and avoid rice and other grains as well as gluten. I haven't taken that step yet. I know I would feel even better if I cut out all grains, but I get so exhausted without carbs. So I'm still somewhat dependent on rice, although it is only a small percentage of my diet.
Anyway, back to withdrawal...
The third day is the worst, so if you can plan it this way, start it on a Thursday (assuming you work a Monday through Friday schedule) so that the third and forth days land on a Saturday and Sunday. That way you can just stay in bed all weekend if you want. Remember, your body is protesting. It is addicted to a poison, like any other drug, and it is rebelling against your decision to deny it what it has become accustomed to receiving at regular intervals. This is normal, and it will pass in a few days, but you will be tempted to eat gluten during this withdrawal period, so be strong. You can do it.
