How about SAD? That's a depression that's due to the lack of light in the winter. Since you're not self-medicating with carbs (SAD makes you crave carbs) you might be feeling the effects more. Also February is the worst month for SAD and many people who don't normally suffer, do suffer from SAD then. SAD sufferers don't have sufficient hormone and serotonin levels to stay on level emotional ly and can have wide swings depending if the day is sunny or cloudy.