Eck I did the same thing recently. Gained 10lbs back, and now its going really really slow.... Sucks.

Lowcarbing still works the 2nd, 3rd..ect times around, it just goes slower and slower. Whatever you do, don't give up altogether and then do low fat, I did that once....I gained. Worse thing ya can do is yo-yo between low carb and low fat.