It is difficult sometimes. I personally am incapable of having "just a little" of anything with carbs or sugar in it. So I just stay away completely. I may in the future allow a cheat now and then but it has to be infrequent and rules-based. Like "only at a party with the family" kind of thing. Otherwise I will completely screw up. I just can't do "moderation."
Anyway, we begin now Marissa. Just dust yourself off, get back on the horse and don't worry about it anymore because people who do best at this don't blame themselves and get all freaked out. They just say "I'm human, it's okay, this is part of my learning process" and without the shame and guilt they actually stick and build their new habits a lot faster.