If you were following the Atkins plan carefully, you would have been lowering your food volume as you go. As your caloric intake diminishes your weight would go down. Any diet will have that effect, low carb or not. Have you reviewed how much you were eating? Atkins is an excellent diet plan, but you cannot keep eating at the caloric levels that got you fat, on Atkins or any diet.

Any diet plan requires careful adherence to the rules and an ultimate reduction in how much you eat. I have found Atkins to be most satisfying and effective. I hope you can either restart Atkins from the Induction level and carefully follow it, or find another plan that works for you.