Eating is a normal activity, however, many of us are addicted to pleasure of eating and we eat too much. I wish there was a sure fire answer to your question. I would talk to your doctor and if you can, see a therapist or counselor. There is a lot they can do to help. Trying to do it alone is not a good idea. You asked this question which is a great first step!
Drink a big glass of water 20 min before your meal. Prepare your portion size & eat only that amount. Eat more vegetables. Raw Salad no dressing. Stop junk food. Come on. You know all this. Play a team sport. Pamela