I've hit this before as well, and have come to the conclusion that, at least for me, detailed meal planning is not sustainable in the long run.

This is one reason why I think that dieting advice that is simple and straightforward has the most success. Some examples:

1. Cut out all sugar-sweetened beverages. This is a pretty easy rule to follow, and even if you find yourself missing a soda or something, my recommendation is to buy something like unsweetened iced tea and then add a couple sugar cubes - you'll be likely to add much less sugar than if you buy sweetened tea.

2. Cut out any refined carbohydrates. This was certainly harder for me, but since the rule is so simple and easy to follow, whenever I got hungry for carbs I had to make due with fruits or vegetables, so I ended up eating a lot fewer calories in any case, got more of other nutrients, and eventually just got "bored" with trying to find a snack and stopped eating until my next mealtime.