> Is non-sweetened cereal hard to find in your supermarket or something?
They aren't. Cheerios is a popular option, it has 1G of sugar per serving. You go up quickly to around 5G/serving for cereals like Wheeties. But milk is where you really get killed: 12G of sugar in one cup of skim milk.
A plain bagel will run you 4G of sugar also. If you are trying to keep your sugar intake to the recommended less than 36 grams a day, it is tough. And then there are the sugar substitutes that may or may not be good for you (e.g. monk fruit in supercoffee).