All the time! Everytime I see someone eating something that's really high-syn and delicious and I don't have the syns for it, I feel like giving up.
Everytime I have a small gain or sts that I don't deserve, I feel like giving up.
Everytime there's a party or a function that I'd love to just go all-out for, I feel like giving up.
Everytime I feel like eating chocolate for breakfast, I feel like giving up.
And everytime I feel like giving up, I think to myself, "would giving up make you happy?" And the answer usually is, "yes, momentarily, and then I'll feel like dirt."
Don't get me wrong, there have been times I have fallen off the wagon, or gleefully leaped from it, rolling in the chocolate covered hard shoulder, but after a week, and a huge gain, I have to admit it wasn't worth it. Yes chocolate is delish, and so are a lot of other things, but they don't make me happy. What will make me happy is the sheer and utter pride I will feel hitting target and being healthy for the first time in my life.
Don't give up, even momentarily... it's not worth it.