I would guess you are experiencing a healing crisis. Even though you have been on the right track for awhile your body still has all kinds of toxins, metals, etc. stored up from before plus everyday environmental toxins. I know it sounds crazy but it is actually a good thing to be so healthy your body is letting go of them. Hang in there and above all drink water! I drink lots of weak green tea when water won't cut it but average at least three quarts of water a day as well. Sugar is addictive so expect some withdrawal symptoms, even now.
Definitely agree with Marcy. Your body is eliminating lots of built-up toxins.
Try some kukicha tea with an umeboshi plum in it to help calm down the upset. And go with the sleep and rest thing....your body obviously needs it! :-)