If you're looking for a healthy fill, I'd say vegetables would be a better bet than fruit. You can eat as much broccoli and cabbage as you like, pretty much. Fruit tends to have a lot more carbohydrate.
To be honest, I've found dietary confusion can be simplified a lot in most cases by simply following the rule 'Avoid Carbs'. I'm not trying to be flippant here either: when I was first diagnosed, I only knew diabetes meant you couldn't handle carbs, so I just cut them out my life altogether. Didn't know how to test my bloods, didn't know much about nutrition, just avoided carbs like the plague. Never felt better. Then, as I learned more, I started working healthy carbs back in- a little bit of fruit, some carrots, the odd slice of bread. Now look at me- fat again. Complete disaster!