Sharon you are better than this.
Nothing worth having is going to come easy, and looking those cream eggs right in the eye and saying "I'm not going to let you ruin any more of my life" is a difficult thing to do. (By the way, doing that in sweet shops tends to get you kicked out of them)
My advice would be to STOP EVERYTHING. Turn off the TV, put down books, sit in the bathroom, lock the door and think. Think of the weight as a big bully, and think of all those times that that bully has put you down and kept you back. Then think about how well you did, think back to the first day on the diet and how you took the bull by the horns and gave it a good kicking and say to yourself... "I am capable of this, and I will do it... and I'm not going to let that bully stop me."
Then play "Eye of the Tiger" ... you'll be more motivated than ever before. There's people here who believe in you.
(just reading that back, I imagined myself on a presidential podium... happy days!)