It's a metabolism thing. I would recommend that you try intermittent fasting. Works like a charm to fix metabolic issues. There are different degrees of intensity, but even the 8 hours on 16 hours off can work wonders. You can increase some of the benefits if you can fast on water only for 24 hours once per week, and then if you get used it, move up to 6 hours on 18 hours off, etc.
In addition, make sure you're getting a good amount of decent vitamins, since you tend to crave eating more if you're deficient in some essential vitamins and/or minerals, and also drink plenty of water (purified water).
As with everything, gradually introducing something until it becomes a habit, a little at a time, is best for long-term sustainability. If you try doing all of this at once, you'll likely fail.
So, perhaps you could do it in this order, and do each step for a month until it becomes a habit and not onerous.
1) make sure to drink at least 40% of your weight in ounces of water, so if you weigh 200 lbs, 80 ounces of water, in addition to other liquids you might ordinarily consume ... and add a good multivitamin once or twice a day (I like the gel-cap ones since they absorb better, such as "Adam" from NOW brands ... and it's relatively inexpensive)
2) try intermittent fasting with 8 hours on and 16 hours off
3) add other supplements to your multivitamin (those which are lacking in multis) -- calcium, magnesium (be careful as too much can cause the runs, so taper up from slight amounts), potassium, sodium (if you don't get enough from your normal diet) ... and Vitamin D3 and C (those two are claimed to be present in multis but not to therapeutic effect)
4) possibly reduce the carbs in your intermittent fasting routine and/or jump up to 6 hours on 18 hours off and/or add a 24-hour water-only fast once per week.
5) add some slight calorie restrictions
6) try to add a bit of exercise, just some extra walking once per day
Probably the best thing about the intermittent is that once you get used to it (takes about 2-3 days), it's really very easy to sustain. With some of the other approaches, Atkins, etc. people tend to crash and fall of the wagon as they develop their carb cravings. With intermittent, you'll see benefits even without calories restrictions or limitations on carbs. But, as per above, you can add some of that in also later for added benefit. But if you fall off the wagon of Atkins, you don't have to be discouraged, since you keep going with the intermittent fasting.