The context of the following conversation is Despite needing to cut back on her sugar, Taylor drank soda.:
Taylor says I was just carving some sugar.  I know I need to cut back on it but I drank a soda anyways..
The friend responds You can drink sugar free..
Taylor responds This one wasn't sugar free.  I feel a bit guilty now..
The friend responds Don't be hard on yourself..
Taylor responds My doctor tells me that I am borderline diabetic so I really need to watch my sugar intake..
The friend responds What's done is done..