sweetlovin-
Just from knowing you here over the past year or longer, what I have noticed the most, is that you have a real issue with an "all or nothing" mentality.
I honestly think that this is your biggest obstacle with weight loss.
You either have to be super duper on plan to the extreme with diet and exercise....or completely off the wagon.
THIS is why you are having trouble, dear.
You have to learn moderation in all things. Here are my recommendations:
~Exercise at a moderate level. Simple. Do a 30 minute workout video, or take a 2 mile walk. Do an aerobics class at the gym. But...don't do all three in the same day, every day, for a week.
~When you slip up, let that slip be IT. Don't get into the "Well, I had a cookie...so I might as well eat the rest of the box..."
In all honesty, eating one cookie, or one portion of something that you probably shouldn't have-won't screw your weight loss for the entire week up. A 200 or 300 calorie slip up one evening will not mess things up for the entire week (It would average out to be only 30-40 calories extra per day over the course of the week!)...but turning that into 1800 extra calories MIGHT.
I think you are having trouble, because you are not learning/practicing moderation. You are either extremely strict with tons of exercise...or you are completely off the wagon. You have to find that place right in the middle.
