Keep in mind that fast weight loss has proven time and again to NOT lead towards permanent weight loss. It has taken you a while to put the weight on and it'll take time to take the weight off. Slow and steady is often time more successful.
Three rules that allow for longlasting weight loss:
1. Get more exercise - do some sort of daily activity and/or do some sort of regular form of exercise 3-4 times per week.
2. Take in less calories, particularly avoiding white sugar, empty calories... processed foods and animal fats.
3. Do not rely on dietary fads or weight loss plans.