You can absolutely loose weight on hormones. They do not inhibit or prevent weight loss in any way. That's simply not true. I've lost quiet a few pounds after being on HRT.
Diet and exercise are key. You need to exercise for at least 1 hour every day, and cardio needs to be at the core. Biking, spinning, aerobics, step, running, etc. is what's needed to get your heart rate up. As far as diet goes, cut the carbs, processed sugars, fat, starches, cholesterol, red meat, and any fried foods. Greens, fruits, vegetables, whole grains, natural sugars, fish, and a small portion of poultry is what I'd recommend. It really isn't that hard to do if you stick to the program.
You just have to do it.