to The Beach, Cabmm!
It sounds to me like you have the infamous "SBD Flu", which is pretty common on the first few days of Phase 1. It's just from refined carb and sugar withdrawal and it will pass soon.
Some ways to combat it are making sure you have your full amount of dairy (2 cups) every day, and including plenty of legumes. Make sure you drink plenty of water, and hang in there. It's all worth it!