Kiki, you might want to consider starting over! I believe that when we "punish" ourselves by restarting Phase 1 again and again we only make things harder in the long run.
Every little slip isn't cause to start over, in my opinion. Now if you are having problems staying OP AT ALL, that is different. Then maybe it is time to take a hard look at WHY it is so hard? I think for some of us (me, definately!) it gets to be like the movie "Ground Hog Day," and we keep repeating the same stuff over and over, including our mistakes. Sometimes the mental part of weight loss is the hardest part!
Your friend is right on the money. You have to try and see success where you can...that will give you motivation to continue, and even to improve where you are able to!