Deciding "IT IS DONE" is never usually anyone's issue.
It's maintaining that decision when you have old feelings, old emotions and old circumstances pop up - that is MOST people's issue. Old energy needs to play out before it goes away. Energy can't just disappear; it needs to run out (or be transmuted).
How long have you been feeding the old story? Feeding it your attention (your currency)
You don't have to learn how to decide, "it is done" - you have to learn how to handle what's coming up. You have learn not to feed the old story "THE TROLLS" aka the old thought, the old emotions, the old feelings, the old circumstances anymore.
How? Attention. Your attention is energy. Attention aka Awareness. Where are you placing your awareness? What are you being aware of?
You keep feeding the trolls and expecting them to go away.
Stop feeding the trolls and they will die from starvation.
It's a habit. Habits can be broken. It just takes practice.
In every moment, you get to choose whether to place your attention on the new story "it is done" or the old story "the trolls".
That's your free will choice. Choose wisely.