@AspieChris
If you have something worth more than 20 lines you
should read through and edit it.
Sometimes I find what I wrote isn't worth saying after all, and don't send it.
Very often I shorten it. Editing is a very good way to improve clarity.
You may have something else going on:
In a sense, when writing you always start with a "stream of consciousness": your personal reaction to something you've read, or your own way of capturing an interesting and sharable idea.
A "stream of conscious" text is by nature idiosyncratic. It's almost always poorly structured for other people, both in terms of the sequence and of content of the ideas, the way they're recorded, and the general readability of the text.
(BTW there are writers who've used it. But only
very good writers can pull it off).
So maybe you should work on getting your ideas structured
before you start writing. Or perhaps review what you've done after each distinct idea/concept has been captured in text.
I've created a
lot of slide sets and class material over the years, and for those I do both of the above, plus a serious edit (and with classes you have to test everything too - it's very time-consuming).
The first step, and one you might like to try out a few times, is to write out the core ideas as "bullet points", with as few words as you can, and no more the the essential ideas.
In this form, it's very easy to get the sequence right, and to avoid meandering (e.g. over-explaining something that's really only intended to contextualize one of the core ideas).
This feels a bit strange the first time, but you speed up quickly. After a while you can do it in your head, at which point you'll be faster and you'll be writing better text.
NB: It's "better" for conveying facts or an opinion. This isn't a technique for creativity (rather the opposite