Did you ever play any fighting video game?
This type of game usually have a thing called "Combo". It is a fun, but hard way to deal more damage to your opponent. For those who are not gamers, It works like this.
The game is all about pressing the right button at the right time and consequently attacking your opponent, who can defend and attack too with kicks, punches, grabs, and sometimes even farts (Mortal Kombat 4 did it pretty well).
The combo starts when you consecutively hit your adversary, and without missing a single time, you keep hitting and hitting it. For every hit you make, you see the combo counter on the screen increasing. 1x, 2x, 3x, 4x... 14x...
The bigger the combo is, the bigger is the damage you inflict on your opponent, but it also gets harder and harder to keep doing it.
That's exactly how our good and bad habits work.
You started your diet and the first day was okay, and then you hold the line for 3 days, then 5, and suddenly you start craving that donut, that chocolate or that ice cream.
At the same time, every day that you don't eat that donut, your body is getting healthier and your willpower stronger because every time you say no, you are hitting that character on the fighting game, and combos are counting! It gets more difficult to keep going, but at the same time, you hit stronger.
You might even lose the count of the combos, and then one single slide will happen and here we are, back to zero again. That's totally fine!
What really matters is what you do next, because now, your opponent, yes, that donut, have a 1x combo on you. Will you let it keep hitting you? You are not the only one that can do combos and you know about it.
Just remember that after every hit, the damage is bigger, so just defend yourself from the second hit immediately as fast as you can, not tomorrow, not next Monday, not in the next month. Just get back to your combos again.