No added sugar

So like I'm supposed to be on a diet that has no added sugars and whatnot cuz I'm fat and have to restart my system or something,anyway,how anal do I have to be about it? Cuz I was told that I can't have white bread cuz it has a lot of sugar,but like so do a lot of other things...like ketchup?do I have to worry about that?or is it used in such a small amount that it doesn't really matter?

Also I have no clue when this is supposed to start but I haven't eaten anything since breakfast (which was before we found that out) cuz the food planned has been not the best for like diets and whatnot,and now I'm gonna have dinner cuz I was told to and apparently aren't allowed to make my own decisions.

P.s.watching a movie to make you feel better after hating everything about yourself doesn't work when everyone's really skinny and you get jealous about it.