Well, I have written myself into a corner. My plot has been building toward a certain scene that will a) reveal vital information about the MC's past, and b) line up the events for the remainder of the story. BUT: every time I think I've gotten right up to the point where I can take the plunge and tackle this scene, I realize I'm not quiiiiiite there yet. There always seems to be something missing, so one more, then one more, then ONE MORE scene that I seem to need to come first. It is infuriating. I've tried skipping the parts I am restless on, and getting right to the parts I want to write, but THAT never works, because I think of something else that needs to come first. So much rides on this pivial point in the plot, it HAS to be thouroughly set up. I am not good at writing out of order either, just because I freeze at the thought of the potential plotholes this might cause. Completely blows my mind. Does anyone have any advice on how to muscle through these last necessary parts, and get on with the good stuff?
If you can't get to this ultra-pivotal event through the natural progression of the story, then I would ask if it's a) as ultra-pivotal as you think it is, or; b) actually part of this story and not best suited for a different one. If the answer to both questions is yes, then just keep writing until you get there. If you force it, it isn't going to feel right when people read it. As for your last question, isn't the necessary stuff also "good stuff?" If it's not, consider cutting it.
I'm with @Francis de Aguilar on this. Write the scene you're building towards. Don't worry about plot holes. Just write the scene. Once you've done that, you can look it over and decide what's missing and bridge the gap. I'm wondering if you're worried about getting this scene wrong—because it's so crucial—and that's what's holding you back? I understand the feeling. However, remember that you're only writing. Nothing is set in stone until you publish. You can change anything that doesn't work. So go ahead and do it. Then work on it. Refine it. Change it. Change what came before, if that's what's needed. And be glad of wordprocessers! This was so much more daunting to do, back in the days of typewriters and handwritten drafts.
For what it's worth my five cents: I know this problem: I tried to write these scenes I was impatient for (in another WIP), only to find that when I actually got there I needed to chuck them. The storyline in between changed this scene so much, that I could forget about it. So it was quite short-lived satisfaction. Nowadays I just muscle through one scene at a time, no matter how impatient I am.
I find Scrivener really helpful with problems like this, it allows me to use a split screen mode so I can keep track.
I'm in a similar situation and the only thing I've come up with is to keep going, bull my way through. Well, not exactly 'bull,' more like: slog my way through drafting each scene, go back and rewrite it so it's at least presentable to me, then tackle the next one. And realize that, at some point, I'll be finished. I think it's this kind of thing that separates those who romanticize writing from those who have come to realize what's really going on.
Yep, that's part of it. But I'm also afraid if I dont have the set-up complete, I'll get it wrong, too. Yes! Not too much romantic about the actual work.
Maybe think of it this way: writing an ending, going back to the middle, and having to throw the original ending and write a brand new one, is still less a waste of time than spending a lot of time not writing anything in the time it takes to force yourself to finish the middle. I gave Scrivener a 7.5 out of 5 star review in the Resources section of this site for almost exactly that reason (although it wouldn't let me give a 7.5 star rating )
From what I've read on this forum (and elsewhere) almost everybody gets it wrong almost all the time on the first try. In my case, I got it wrong for for seven full drafts. I came to this realization back in around February this year. It took me a while to get past the disillusionment, the angst, the... well, you get the idea. Then I got started on draft eight. Right! So, you ready to get back at it? Wanna race?
So then you can fix what's wrong. Once you know what you actually need, anything can be fixed. If your major chapter requires three people to arrive at the train station at the very last minute, you can carefully plot it all out beforehand. OR you can write the major chapter as you want it to happen, then go back and make sure all three of your characters are in the right place before the scene starts, so their last-minute arrival will be plausible. A crucial scene can be overplotted beforehand. If you lose your excitement in fear of making some mistake, the writing can become flat and uninspired. Any actual plotting mistakes can be fixed later on. What can't be recaptured is that sense of discovery.