I wouldn't say it's writer's block altogether, I think it's just the "stretch" of trying to communicate something you haven't effectively communicated before.
The analogy I would use here is– it's like a standup comedian trying out new jokes. He knows that it's funny, but the audience isn't laughing– because there's something about the delivery that he isn't getting right.
My advice for people struggling with these things is to do multiple drafts. Try to write it down, then start over altogether from scratch. Explain it to other people. After a while, you'll start "catching" the right turns of phrases and sentence structure and so on.
Absolutely. This is so important. The writing and editing process should be decoupled– trying to do both at once typically leads to frustrating contortions.
(I still struggle with this, not preaching down at you from a high mountain. Very far from that in fact.)
We lose the ability to look at our work objectively after spending a long time struggling with it, if you can put your writing aside for a period of time (some people say a few days others a week) stuff that you thought looked like dreck can turn out to be promising or occasionally perfect.
Usually, I'm fine with the creative aspects -- I know what ideas I want to communicate. What troubles me is finding the words to say it. And the more time I spend thinking about it, the more difficult it becomes. Sometimes, I can spend an hour working at a paragraph, and still can't get comfortable with the wording.
Does anyone else have this problem?