There are times when the story flows, when you can write one or two thousand words at a clip. There are times when the story takes over and you are amazed by the twists and turns that develop and the responses of the characters. There's no better feeling for a writer.
Then there's the opposite. This happens when you don't know what to say next, when you have to think about the story word by word and struggle through each new development, and it's hard work.
What then? Either you can give in and give up, for a while or for a long time, because you are "blocked." Or you can forge ahead anyway, without inspiration, in which case the writing likely feels stitled, overly artificial, and joyless.
I suppose that everyone who writes is familiar with these different experiences. And I suspect that it is the same with all creative endeavors.
Assuming you do forge ahead, writing slowly and painfully through your blockage right to the end of the story, the question is, What is the final result, and how does it differ from inspiried writing? And do you think your readers can tell the difference?
My hesitant opinion is that they will not know.