It's never easy but sometimes you have to recognize when to bail out of a story.
I have to admit there are times when I work really hard on the structure of a story...then come back to it six months later.
As a boy, it was difficult for me to learn cursive writing. I hated it. But I tried to stick with it and my teacher slightly frightened me when she said, "In cursive writing you must always keep your pen on the paper with every word. Do not lift up your pen in the middle of a word. You are essentially bailing out. If you do this, I will know it."
That haunted me for a while because keeping pen to paper was a challenge to me. But there were days when I did lift the pen. And you know what happened? My teacher never even noticed. I got good marks on my cursive and my little felony of lifting the sacred pen went unaddressed.
I'm not saying that that makes me an expert and that I should pursue a life of crime in forgery. I'm simply saying that if you feel that you need to bail out of a story, it is perfectly okay.
Either you have to bail out because you need to abandon the story completely because it doesn't work or you need time for the idea to settle and meld better so that you can come back to it later.
When writing my first science fiction novel, there were several times I had to bail out and walk away, promising myself that I would return to finish the story. In order to blend myself back into the story, I reread everything I had written before. So if I had 200 pages written, I'd sit down and read all of them before I wrote another word. It was tedious, but I felt needed.
There have also been times where I had to bail out of a short story because initially, the idea was interesting but it didn't come out on the page. I would actually say out loud, to an empty room, "What the hell is this? What was I thinking? This is just a bunch of words on a page. A word salad. There's no story here. Time to get outta this mess."
But I learned something crucial to writing: Always make sure that when you come back to the page, that the same passion, drive, inspiration and creativity come back with you. It will be a challenge but one that will ultimately be rewarding in the long run. And it will appear seamless. Like you never lifted the pen from the paper at all.