Hi chillout
When we eat sugars either in sweet things like chocolate, processed foods or in processed simple carbs like white bread for example, our blood sugar rises then falls dramatically. In terms of brain chemistry, the effect is very similar to that experienced by heroin addicts - put simply, we crave more and more, which is why things like chocolate can be genuinely addictive to many people, diabetic or not.
Sugar addiction can be broken by eliminating all added sugars from the diet and limiting intake of starchy carbs (bread, pasta, rice, potatoes and flour). For a week or two, you may experience headaches and cravings as your body tries to 'trick' you into giving it the sugar it wants, but if you can stick it out, these will subside quite quickly.
Following a balanced reduced carb or low GI diet will help to curb sugar addiction and is healthier all round.
There is plenty of information on this forum about low GI or reduced/low carbing which many diabetics find helpful in managing their diabetes. If you need any help or information, please ask as many questions as you can think of - we are all here to help.