I gave up sugar as a teenager as my dentist assured me that I wouldn't need fillings again and I've not had any since. I gave up sweeteners in 2012 when I gave up Diet Pepsi. I really didn't think I would ever be able to give up sweeteners but I did.
The trick, is to gradually reduce all the added sugar and sweetener items that you eat - the cereals, jams, jellies, soft drinks, tinned soups, condiments etc and to have higher cocoa solids chocolates. As your body gets used to less sweetness, you'll find that your tastebuds become more sensitive. I can taste the lactose in milk and smell sugar in tea. Eventually you just won't like them.
I watched a doco with Stephen Nolan on catchup tonight and a doc was saying that sweeteners can be just as bad as sugar, because the body can't tell the difference.