Hey! One day isn't going to ruin it believe me. There are 3500 calories in a pound so it's extremely unlikely that you would have put on any weight whatsoever. If you've put any weight on at all it will just be glycogen and water stores that are topped up. Sometimes you have to listen to your body as well and eat what you want. I mean I'm training to be a PT and I am cutting/dieting at the minute but I ate well over my maintenance calories yesterday and have hardly been to the gym this week due to illness but it's fine because I'm back on track today. Look at the bigger picture and look at it from a weekly perspective not day to day.
It depends on how you look at a cheat day, is it a day where you eat what you want or is it a full on binge? That's where your discipline kicks in. I don't think you should have a cheat day next week because you've already refuelled your body. Cheat days are just a way to justify eating a lot without restriction but a better way to do it would be a refeed, where you eat a couple hundred calories over your maintenance) however I would have one in maybe a couple of weeks time. What I would do is have a think about what I would like to eat on that cheat day and incorporate it into my calories throughout the week so that way you can eat whatever and still stay on track. You can still eat chocolate when you're cutting by the way, just make sure you put it into your calories.