Have you ever had therapy to deal with the emotional issues that your weight is a symptom of? If someone is a number of stone overweight and has struggled with it for a long time, it is never a 'simple case' of eating less and moving more. Obesity is as much a psychological problem as anorexia - the key is not the weight loss method, which is pretty immaterial. If you have surgery, but do not face and properly deal with your emotions and your relationship with food, you will almostly certainly put it back on. Good luck!