My doctor gave me some excellent words of wisdom when I complained of my difficulty in losing weight: You didn't gain that weight in a short time, and you can't lose it in a short time.
Moderation and healthy habits are going to be the only way you can safely lose weight - not gimicky diets and not diet drugs. It's going to take a while!
I needed to lose 150 pounds (YES 150!). I've only lost 40 in the last year and a half - then I gained some of that back after breaking my foot - couldn't move around very well.
However...my blood pressure is now completely normal, as is my blood sugar. I'm gradually getting around better, and hope to start riding again soon. Doctor is actually pleased with the weight loss, and I hope to keep it up. I don't care that it's taken this long, I can tell the difference in how I feel, and so can my family!