I wonder if you have tried straight forward calorie cutting? trying to keep the nutrition side happy (getting enough protein, fresh fruit and veg, drinking enough water...etc) this works. Its not easy though but it works. The basis to any weight loss is more calories going out then coming in. Its easier said then done but just cutting calories will work from a scientific point of view.
Even the pills your taking; based on the same thing, they just work on taking fat out of your body at a rate too fast for them to be absorbed. Personally I'd find this worrying (and trust me, theres not an awful lot I wouldn't do to lose weight right now!) but messing with food you take in, with such a bulimic type of process (purging) just concerns me, not only because it doesn't teach you healthy eating, you learn how to miss out fat from your diet to prevent the side effects, but it doesn't teach you portion control or what foods to eat to be healthy.
I'd get some professional nutritional advice, watch your calorie intake. It wont be easy but the longer you hack at it, the sooner it does become easier and the more possible it is to stick with it.
Your ideal weight loss is around 2lbs a week max. Any more then that and its coming from water, glycogen (carb storage) and muscle. Not body fat. Infact you will always lose a little muscle whenever you lose weight (hence the importance of muscle training to help rebuild and retrain what your body tries to tear down for fuel, it wont all get put back but some of it will) the smaller the weight loss, the more of it is likely to come from body fat rather then muscle.