Do you think it is possible for ANYONE to lose weight after baby?

Before baby I was a healthy 117 lbs. and i'm 5'4. I have been trying so hard to get rid of the baby weight I gained while pregnant. I am coming up empty. I have tried weight watchers, atkins, southbeach, the zone, and the 6 week body makeover. I do great for like a month then I just binge and get depressed and stop and gain it all back. Do you think it's possible for ALL women to lose that weight? Should I even worry about it?