Why can't I lose?

You people are truly awesome and I thank you so much. I am going to take all your suggestions into consideration. I will definitely try to eat the 1200 plus exercise additions by adding in some of the suggestions you have made. It has only been a couple of weeks since the weight seemed to stop coming off. Maybe I jumped the gun and assumed I wasn't losing - maybe the scale just isn't showing it. I wish I could exercise more strenuously - I used to walk/run wayyyy faster than I can now, but have to accept my limitations. I feel that as long as I am getting myself on that treadmill and staying on for an hour, even if it's a slow pace, I have to be doing something good. The only days that I don't walk are the ones that I work. I am a substitute secretary for a school division (my retirement job) and when I'm working I do move around alot - big schools! But when I'm home, other than the hour on the treadmill, I am fairly sedentary.
Thanks again for meaning so well and trying to help a total stranger!