Yeah, I suspect some variant of this is universal for any sort of longer project, though the precise order and timing of ARGHs is individual. I'm currently in "But wheeeeeen will this ever eeeeeend????" angst with a WIP and I relate so hard. (Answer: it will end in four scenes, penguin. Get off your butt and write them.) I wish you a speedy transition into actual completion, or at least stage 4.