Simply walk away. Get out of the house and away from the kitchen. Eat a single serving and put the rest away or go out and make it an event. Then add 15 to 30 minutes only your workout the next day to counteract the unhealthy food. A support group can always help as long as you know that the main support comes from within you.
Motivation comes easy at first.
After awhile it begins to feel old. Reread your list of reasons and goal. See how far you have came. Keep a journal and note how much weight you have lost. Count how many more minutes you can run or walk.