Weight Watchers

So kinda on a whim, after work I Monday I signed up for Weight Watchers online. I did it in college so I'm familiar with how the diet works and so I thought I should try it again. I had some success with it but like all the diets I have been on as soon as I plateaued I became frustrated and went back to my hold habits. I am determined that this will not happen again. When I weighed myself to set up my profile, I was horrified to find that not only have I gained back all the weight I had lost before moving to New York but I am now the heaviest I have ever been! When did this happen? I don't feel like I have changed my eating habits? I'm not eating more then I did before. I'm actually more active here in New York then I ever was in Iowa since I don't have a car and am forced to do more walking. So how can I really be heavier now then ever before? This puzzles me but I want to look as this as a good thing. Maybe this is what I need to push me to really lose the weight. I refuse to gain anymore weight. I wanted to lose some weight before we go to Florida in March but it's no longer about that. I'm not happy with the way I look. I know I am not healthy and I have been overweight for most of my life. I know this is something I can change and God willing this plan will help me do it.