That's interesting - I have chronic congestion. How much sugar did you eat before you quit? What did "quitting" mean to you? (Just no sweets/cakes/biscuits, or did you go more extreme - no chinese food!?)
If I have almost any dessert now I'll have a sinus headache the next day. I can get away with a teaspoon of honey in the morning and that's about it. Berries are ok but I'm still not sure about fruit (bananas are definitely not ok). But I can eat good bread three times a day and I'm fine.