Sigh - take the advice you got and do almost the opposite and you might get somewhere - no bread no potatoes, but there are no added sugar and high cocoa chocolate bars in just about every supermarket, and you can have a few squares of them every day - as long as the no added sugar ones don't upset your insides as they have sugar alcohols as sweeteners.
I went from 91 to 47 at my second Hba1c test, and it wasn't at all difficult to do - I was thinking a year to get down into the 50s perhaps, but it was much faster, now, after 6 months from diagnosis I am trying to get weightloss started again and it seems I have succeeded. LCHF seems to work like a charm for me. I know it isn't magic, it just feels like it is.