mt- I would agree with you if your doctor is open to diet and nutrition. If not find a doctor who is open to wholistic health. This would include (in addition) herbal and homeoapathy, acumpuncture…
Ask your hopefully Natural Doctor for a sensible and Nutritious Diet Plan. Set realistic goal as far as how much weight you want to lose and the time period you want to lose it.
Join the Gym. Burning calories is a great way to lose weight.
Say Tehilim and ask Hashem for guidance for finding the right doctor for to help you lose weight.