The only way you will get over your sugar cravings will be to stop eating sugary or sweet tasting things. I would advocate for *more* exercise not less. Afterward your body will be primed for primal foods -- protein and fat, vegetables, once consumed they will counteract any cravings you would have had for sugar.
It's not going to be easy - there will be times you really want something sweet after dinner but you'll need to fight through it.
Once thing I can recommend is
It kills chocolate/sweet cravings very effectively and tastes great. A terrific way to transition to more primal fare.
a heaping tablespoon for every 8 ounces is a good measure.