Ashish, I would encourage you to use the upcoming Challenge to leap into your story, pound out pages, and see where it takes you.

That said, I suspect the reason you got stuck was because you have not figured out what your Protagonist is ultimately about. Why do they have to go on their journey? What is their deepest need / unconscious goal? If you already have an ending, you may be close, but you still may not figured out how the Protagonist gets there either/both in terms of the Plotline or their psychological journey.

Suggestion: spend more time with your characters, especially your Protagonist.