I've had sugar hangovers in the past. They can be remarkably similar to an alcohol hangover.
During those first few rough months when I got sober, sweets were a life saver to help me deal with cravings. I ate a LOT of red velvet chocolate cake with cream cheese frosting.
I never had a Day 1 with sugar, but over time I have generally cut out sweets and refined sugar. It's really nice how sweet some fruits like grapes and strawberries start to taste once your body adjusts to not having refined sugar.