I weighed more than you at one point, so I know how you feel. The best thing you can do is ignore what everyone else has to say and focus on what your body tells you.
There are lots of great support groups around the site, as well as sites for fitness programs and for specific diets. Whatever you need, chances are you can find it here.
If you're very unsure of how to start, I agree that you might be best off consulting a doctor. If that's not an option, maybe try eating normally for a week and logging you calorie intake with a program like FitDay. Then, after a week, you can cut back your calories slowly until you find a range that helps you lose.