How to not gain weight and start eating normally after a low calorie diet?

As long as you continue to perform cardio 3-5 days per week, you should not gain your weight back. Especially considering your only upping the calorie intake by 200-400, I do not see where there should be a problem. Just make sure are consistent with diet and exercise. If you start to trail off and stop doing either, your weight will come back. Hope this helps, and good luck to you!