Hey John - don't worry! You know that bodies aren't totally logical and predictable - children don't grow at a smooth, regular rate, or even in proportion (ie the feet often grow first, or the legs get long and gangly before the rest of the body lengthens etc), but it all evens out in the long run. Well, in my experience, LL is like that too. Some weeks you can lose loads (though never so much as the first week, because there you're losing all your glycogen) and other weeks less. But it's all loss, and it's the way your body needs to do it. And I also think this is the fastest you're ever going to do it without damaging yourself - believe me, I've tried almost everything else! So my advice would be to keep on having the foodpacks and drinking the water, but don't think about it too much. Get busy with something else, and the weight will take care of itself. About the chip - well, it certainly won't help, but put it behind you and if you want maximum weight loss (and minimum guilt) don't play around with the food. Even if you are 100% virtuous, though, you may still have erratic weight loss. I'm on week 11 now and have never cheated but I'm in a 2-week pattern: week 1, lose between 1 and 2 lbs, week 2, lose between 4 and 5 lbs.
Maybe you could lose 3lb a week at WW (though being female, I never did - grr!) but you'd be surrounded by food and choices and for me the temptation to cheat and play around with points and allowances would be overwhelming, so I wouldn't last more than a few weeks. At LL we all have lots of weight to lose, so we have to commit to the diet for the long haul, and this is the best way I've found to stick to a diet and keep the weight falling off, even though the body acts in its own sweet (and sometimes annoyingly slow) way!
Well done on the exercise, and on your terrific loss so far. You're doing really well and next week you will probably have a good loss - though don't expect another 12 lbs! But even if you just lose a little, you're still losing and you will get to your goal if you just keep going... Best of luck!