Carb flu is the achey/yucky feelings which is normal. it's a sort of clear-out -- particularly if what you ate had a fair amount of chemicals in addition to that which is in grains that makes us feel yucky (but we're used to it after a while because yucky = normal).
For sleep, I recommend winding yourself down early. Turn off tv/computers/etc at about a half hour or hour after sundown, then go with dim lighting or candle light and conversation and then into quiet and bedtime. it can help a lot.
In regards to food, in addition to recording what you eat, go ahead and count calories if you like data points. you might notice that an adjustment of 50-100 calories either direction could make the difference for you. If you are forcing yourself to eat, consider eating a little less if yu want to eat meals every 4-6 hours.