You can train your mental strength just like you train your body. If your body looks fit or ripped, it looks strong, and you can flex your muscles. So, physically, you have a certain strength. Mentally, it's the same thing. You can train your psychological strength.
In falling over in heels while trying to look attractive, you don't just hurt your body, you bear the humiliation of injuring your very soul. Physical pain? Whatever, bring it on. But the humiliation? Oh, you have seen to the very weakest part of me.
Try not to completely change your diet just because you read it somewhere or someone tells you it works for them. Do what is best for your body and don't think that just because everyone else is doing it that it will work for you. Know what fuels your body to be at its best, and enjoy the little things! Indulge! Cupcakes and cookies.
I think it is really important to indulge on the holidays, I think that we all deserve that; I think that the more you worry, the more it's a problem. I think everyone's relationship with food is all about giving your body what it wants and what it needs. I think indulging is good and working out, too, for sure!