@ManyMuses -status- I'm not sure there's a set time, but there are some good ways to destroy it before it disrupts any further!
1. Sit in a comfy place away from distractions
2. Put on your favourite song
3. Imagine the story in your mind. But don't grasp at it. Hold it lightly in your mind. Imagine you're opening the front gate to the world of your story. Imagine all your characters there, and what they all would say to you, their creator.
4. Then open a notebook and grab a writing implement like a pencil or pen. Write down a question, and, one at a time, write down each character's answer. Now you've gotten back inside your character's heads, reread all your old notes.
5. Now try and carry on the story, or you can write something completely unrelated to the plot, but either way, start scribbling something!
6. Now sit with a cup of [insert hot, calming, immensely enjoyable beverage here]. And let all these things sit awhile in your mind, until you feel ready.
7. Now carry on the adventure...
**I hope this helps! This is what I do personally, so it may not be effective on everyone. Still, I hope you get over the block soon!**