I've lost my motivation

Yep.  Gone.  Totally gone.  I've been bad.  I'm snacking, eating high calorie foods, and not even trying to be more active.  I've gained weight instead of losing (no duh after what I've been eating!!), and I am at a loss on how to get that motivation back.  I started losing my motivation last week, but tried to hold on.  Then came the weekend.  I swear, I am always bad on the weekend.  I have no self control.  Anyway, it was William's birthday party.  I worked my butt off in the morning cleaning the house, which I thought would counter act some of the bad food I was going to eat (pizza, pasta salad, cake and ice cream).  Then, I just stopped caring.  I haven't logged in my food intake into myfitnesspal for several days and even ate ice cream the last 2 nights.  I can blame some of this on my period.  My cravings and just general appetite increase during my period.  I also get bad PMS, so I am hoping that that is another reason why I don't care.  I want to care!  I need to care!  But, I just don't right now.  I was very motivated in Jan, and now I'm not.  Not even close!  I tried to get inspired by reading weight loss success stories and watching the biggest loser.  However, nothing is getting me to want to do anything.  I am turning into that fat, lazy person I've always been.  I hate this!