Try not to put too much pressure on your self. I find that if I am trying to lose weight for a specific reason I go off the plan because I try too hard. Just take every day meal by meal. Make the best choices you can and I'm sure you'll see a loss next time.
Did you stick to plan or do you know why you gained? If you don't know why, did you keep a food diary? Did you check syns and HEX weights? Is it star week?
Don't be disheartened, pick yourself up and dust yourself off and start again. Good luck.