I believe the key to sustainable weight loss and healthy living is obtained through positive lifestyle changes. These are so simple to say, but for many they are so difficult.
They involve long term dietary changes, not quick weight loss schemes. It's important to get on an exercise program, that's good for you. Always consult a doctor about any exercise or diet program, especially if you have high blood pressure or any other health problems.
Also, a lot of weight gain could be caused by emotional factors. Remember that you are a beautiful person and that you can change to even a better person. As you slowly improve, you find yourself helping others and it can be self-perpetuating.
I'm one of the few people that have lost weight that way, and I've kept it off for about 17 years. I also run nearly 20 miles a week, after years of sickness, and not being able to run at all.
Set your goals to sustainable levels, like I'm going to lose a pound or two each month. Be happy with that small result, not trying to be "skinny" immediately. Once you reach these lower levels, make every effort not to yo-yo back. Dietary changes, in my opinion, mean not eating any sweets or drinking alcoholic beverages (some wine could be OK). Avoid processed foods, and eat natural foods that are filled with vitamins and minerals etc. Look at this as a lifetime commitment that involves a lot of research and it's a lot of fun too. Tailor a plan that fits best for you.