FELL OFF TRACK! PLEASE READ....

For the last week, i have not worked out and my diet has been awful, as if I dont record what I eat which I havent for the past week I over eat and eat things I shouldn't. However I have only put on 1 pound. Tomorrow I am getting back on track but I have a question. June 30th will be my birthday and I am hoping to lose 6 pounds by then. I wanted to go on a low carb diet so cutting out 80% of the carbs I eat for lunch and dinner. But what I'm worried about is that I will have no energy to do my workouts which is 40 minutes high intensity cardio for 6 times a week. Is it a bad idea or should I be okay to do my workouts.