well 500 calories is too low amyway. A 1000 calorie diet would be more realistic. If you focus on high protein low carb foods. Be sure to incorporate vegetables to help you feel more satisfied. You can do this but set realistic goals for yourself and be nice to you.
My son is trying to lose weight, too. I told him, when you go over your count, just exercise a little more that day. Some athletes have to consume around 10,000 calories daily because of the exercise. It's all good.