Me: BW, divorced, now fabulous and happy!
Don't waste any more money on stuff like this. Do you think that if there were some magic thing that you could ingest, that anyone would be overweight?
This part of your post:
it seems impossible no matter what diet I do or what I take
is very telling. It's not about a diet (in the traditional sense) or supplements.
It's about changing your lifestyle, for the rest of your life, that incorporates mostly healthy food and exercise, including strength training.
http://www.nwcr.ws/Research/default.htm is a link on how people who've actually lost weight and kept it off have done it.
Most people don't know what "eating healthy" really is. This is one of my favorite links: http://www.whfoods.com/
Anecdotally, it seems like diet is more important for losing weight, but exercise is more important for keeping the weight off. Every person I know that has lost a significant amount of weight and kept it off for more than a couple of years exercises.
You can do it, but it's tough work until it becomes routine. There are no quick fixes, and anyone who promises one is a charlatan.
Married: 11 years, no kids
Character is destiny