Don't fret too much, you should be proud of yourself for getting back on the wagon.
It happens, holidays can be bad, but you are making a wonderful decision to get back on track now, instead of beating yourself up for another few weeks. Or months. EEllleek, I've done that, but not anymore.
I used to be really bad about falling off again and again, but something that turned me around, and changed my life, (I swear) was getting a diet buddy. (online) This forum is wonderfull, don't get me wrong, but when you have one person to talk with EVERY day, it really helps to stay on track. Not only becuase they are there for you, and support you, but because you have to be there for them. Its much harder to let someone else down, then let yourself down. Some days the only thing I would do is talk to my buddy. But she would lift me up, and when she was down I would do the same. It gives you a sense of empowerment to help someone else, and to me is healing.
I will warn you though it took a while for me to find a person that I was compatible with, and that was compatible with me as well. I had to search for a few weeks, but when I found her that was it !!
Oh crap, I will feel dumb if you already have a buddy, but if not, try it !!
and if so, oh well at least maybe someone else will read this and be inspired.
Good luck to you, and congratulations for getting back here !!