and, of course, once you have succumbed, it's harder still because you're out of ketosis... you need to get plenty of protein in. Perhaps buy a cooked roast chicken next time you dash into a supermarket - exceptional circumstances and all that (remove skin, pat at any fat with a piece of kitchen roll...).
The weekend's coming up... get things cooked and frozen in packages for lunches and dinners. Takes no time at all, and easy then during the week when you're short of time to just grab a package and run!
For that dress Saturday, stick to pp and remember your oatbran x