I 'play' the story in my head all the time... even when dreaming... but when I sit down to add what I've thought of or dreamt of, it doesn't seem to gel with the main plot, and I get really frustrated.
It's not like I'm trying to write the Great American Novel... far from it. It's just another horror story.
Well, no advice on how to end, but for the love of God, when the sexy teens finally figure out that a hideous monster is trying to kill them, have them get the gun out of the closet, not the flashlight...I hate that!!!
Problem solved! Just make it exciting and scary and stop worrying about it!!
Oh, and one more thing that works for me: sometimes if I get stuck, I'll head for a different setting. I'll take a notebook to another room or a park or anywhere other than my usual spot.
But honestly, it sounds like perfectionism is your biggest problem. Get it down - smoothing over the lumpy parts and tidying everything up comes later.
We're gonna have to force you to do NaNoWriMo with us this fall to help you beat your internal editor senseless for awhile. ;-)
Hmmmmm
You get extremely frustrated.
How frustrated are you typically in other areas of your life?
If you are a bit too obsessive, you might practice LETTING THE UNCLOSED CIRCLE BE.
Let whatever is niggling at you be. Lay it aside; ignore it; attend to other aspects. There are some good suggestions hereon for that.
There is plenty of time to come back and deal with the niggling parts.
The business of writing the last chapter then the 2nd to last etc. is a good one.
You could also do something creative like writing the opposite of what you'd think you'd want for the next chapter.
Or write a spoof of the next chapter.
The principle of brainstorming is that any silly idea can spark a great one. Trust that as you do something--almost anything--things will evolve.
Well, this will either help or reveal me as a nutball, but I 'see' everything like a movie, then just write down what I see and hear. The only time I've been stuck is when 'I' get in the way of the story and try to put things in that I want to see happen. The best dialog has also been the stuff I've just heard. People talk to me in the shower-lol!
Someone further up also had good advice- write the end first. I co-wrote my first novel was done that way. We saw the beginning and the end and all we had to do was figure out how I could logically get from one point to the other.
It's also nice when things just write themselves, coming so quickly and smoothly that its like taking dictation. I've heard people say that art, like writing and music etc, comes THROUGH us not from us. In at least one case I can tell you that that is true.
Good luck. Back away. Try another perspective- and listen.
But THE most important thing you can do, is to NOT EVER POST GARBAGE, BANAL VANITIES TO FR ANYMORE AND MOST ESPECIALLY NOT TO THE NEWS SECTION!