On top of restricting your caloric intake and exercising, you should also be restricting the types of foods you are allowed to eat during your weight loss journey. If we're limiting our discussion to what you see on the scale, 100 calories of white bread is equivalent to 100 calories of chicken breast. However, the chicken breast will provide more satiety (make you feel fuller for a longer period of time), thus limiting the likelihood of overeating and promoting weight loss.

Generally speaking, protein > fat > carbohydrates for satiety. Foods high in fiber will also keep you fuller for longer (like beans, oatmeal, leafy veggies).

You need to adopt a systematic way of shopping for food. Some ideas: no fast food, nothing that comes in a box, nothing with more than 5 ingredients on the nutrition label, all foods must provide at least 5g protein per 100 calories, impose a strict food budget like $20 per week (think of it as a game or challenge).

You are very fat. If we're being realistic, exercise isn't going to contribute much to your weight loss (your size probably limits the amount and type of exercise you can do anyway). You should still be doing it though -- for building good habits and mental fortitude, not for weight loss. Exercising is a very inefficient way of losing weight.

Hope that helps.