I have a strong suspicion it's related to my eating habits. there's a strong correlation between how much sugar I eat and how I feel mentally. I was fine for a week when I was eating right again, but
for the last year I was doing great replacing snacks with protein bars and green smoothies, I just dropped the ball in November and got back into my old habits
Eating well during the holidays is always hard for me, too. It's awesome you have the insight you have linking your moods to foods! You'll get back on the wagon and feeling great again in no time.