Have you ever done any dressmaking? First you are down on your knees fitting pattern and fabric together - pins in your mouth, scissors at your side. Then you take your work to the sewing machine and put it all together with tiny, perfect stitches. But after all the blood, sweat, tears and creativity - it doesn't fit. You love it - but it's not quite right. The skirt part is okay, but the collar is all wrong, the belt's an inch too high, and it's a bit snug around the armpits. Nice bodice though. Too bad it has to be either taken apart and re-sewn or given to someone smaller and thinner.
I've never actually been able to sew, but I remember knitting a cardigan, following the pattern religiously, and the finished cardigan was absolutely lovely - but three sizes too small. I know it was three sizes too small because that's how many times I had to unravel the thing before it finally fit me. I had to change the needles and I had to change the size. The pattern hadn't worked for me.
Well, now I'm unravelling parts of my novel and putting it back together. I loved it the way it was, though now I see some of the errors of my ways. My publisher ripped into it the way a bunch of kids rip into a birthday pinata. My brilliant editor was gently critical, offering possible solutions, and doling out a little encouragement and praise when I actually came up with some solutions to my own problems.
Today I felt I needed some distance, so went back to another unfinished masterpiece-in-the making. I hadn't looked at it for months, and now I can see it with fresh eyes, as if someone else had been writing it. 'What clever person wrote this chapter, I wonder? Oh - t'was I!"
When a cardigan goes wrong, knit a scarf until you're ready to go back to it.
When the dress doesn't fit, sew something else for a while.
When the novel is in pieces and spread all over the floor, go back to one of the other stories you have on tap. And don't tell me you don't have any. Every writer has a pile of unfinished stories.