First and foremost, I think that you should be very proud of yourself for the progess you have made.
You mention that you have gone from nightly binges to one binge per week. So at the very least you know that you are strong enough to effect a change in your life.
When you feel the urge to binge (and I am not merely talking about a carb up - but an all out uncontrolled binge!) you could try simply supplementing with fiber and water (psyllium husk powder is excellent for example - two tea spoons in water will make you feel extremely full - perhaps killing the urge to eat). Drinking lots of water throughout the day will also help in this regard.
But I think that your best bet is to remember that you have made progess and that you CAN DO THIS. The power of positive thinking can do wonders.