It's hard to say... I imagine you've been crying and perhaps the food binge created mucous after five days of no eating (You did say you were fasting for five days right?) When I am emotionally upset, or when boulders fall on my head, and I have been crying, my head and my nose are always stuffed to the point of pain... Then again, for you, this could be latent detox symptoms... ready to rear their ugly heads just before the boulder crash landed. And it could be as simple as a bug invading your system when it's most vulnerable. Emotional upsets can wreck havoc on our immune systems sometimes, making us susceptible to all kinds of bugs.
Should you choose to resume your fast, and if this is a nasty bug or detox symptoms, drink green juices with garlic (disguise with sweet carrot/apple if you like), hot lemon tea with cayenne pepper and you'll kick that bug in its sorry arse, pronto.
Seriously, I do hope you're feeling better soon. It's a challenge enough to do a juice fast, but to add a serious emotional upset to the mix can bring the most stoic of us down. Hang in there... Be strong.