I know that you may be able to get a range of the types of diet candy you may be seeking at Walgreens. You could also check out Diet Direct.com where you might find something that suits your requirements. I hope you will really find what you may be looking for eventually.
Diet candy in itself is not healthy because they have a lot of artificial sweeteners and ingredients that they put in there to replace the sugar taste. Diet Candy is usually geared towards diabetics. What you need to find is low sugar, low-fat, organic and whole ingredient foods.
I did try this with all typs of soda and it worked. I was never able to do it with candy though. It seems sometimes I just really crave it. Doesn't help at I love baking either.