Now that I've gotten used to this

I wonder how easy it will be to get derailed while not on vacation?  Like, now that I'm used to having my coffee with half and half, a protein bar for lunch, and then a decent sized, low-ish carb (no grains) dinner,  will I fall off the wagon come winter? To do that would mean abandoning my whole method. Will Christmas do me in? I do want to enjoy Thanksgiving and Christmas, etc, but if I stick to the "eat only leftovers for dinner, not for lunch and dinner", maybe it will be OK? And for Christmas, I can just try to avoid the holiday goodies, but will I and could I long term really say, "oh, no more baklava, sugar cookies, etc because mom can't eat them."?

I'm trying to anticipate my stumbling blocks as I know I'll have them. How do I prevent it? How do I continue to stay on plan easily?

A person on a forum I peruse has been enormously successful with maintaining her weight loss, yet she says that she spends a big amount of mental energy and time thinking about what she will eat, how she will eat, etc so that she doesn't gain weight. That constant mental battle can be exhausting and can lead to failure. I don't want to be relosing again for the umpteenth time! I don't want to be a human yo-yo!

And those are my thoughts as I'm getting ready to end my fast for the day - thinking only about eating at this point, especially as I ate a light dinner last night.