Gaining and losing and gaining

I got my period Tuesday. It is always harder to abstain from sugar around my period. I crave sugar especially chocolate. Also I get PMS. I was really depressed yesterday and couldn't get myself to go exercise. I didn't want to do anything. I had no excuses other than I didn't want to!! I didn't feel like it!! The difference between me and the other people at the gym, besides the fact that most of them are thin and I am fat, is consistency. They consistently go whether they want to or not. Whereas I go with the object of losing weight. If I start binging and therefore not losing weight, I stop going! I need to stop seeing my problem as a weight issue, because then I think the problem is gone once the weight is lost. Actually it gets harder to maintain good eating habits once I am thin, because there are no immediate consequences from eating candy and junk food when I am thin. Unfortunately, I forget that that one candy bar is usually the beginning of more candy and more junk food, and not being willing to stop until I gain all my weight back plus more. Because once I start eating sweets, I don't WANT to stop and the only thing that stops me is being in more pain from eating sweets than not eating them. That usually happens when I am fat again and no clothes fit and I have trouble going up stairs and I hate myself again!!!