I hate it when I have a gain.
I weigh daily but only record weekly on a graph on my laptop. This week I'm not surprised but I gained. 1.5lbs and a 2lbs increase from yesterday. So I know it cannot realistically be fat. And I know that weight loss is like this. The data is spotty it will go up and down even if the overall trend is in the right direction.
But all of that rational mind doesn't work when you feel like crap because all your hard work feels wasted.
Just venting. I know the advice, I know I'd tell others "it doesn't matter, no doubt you'll lose next week" but still discouraged.