I got back to writing longer texts by mentally separating writing and editing. When writing, just write. Even when you think the paragraph could be better, keep on writing.

Only start editing when a substantial piece is ready. Clean up some wording, rewrite a paragraph or two.

Even then, don't overdo it. There is always something to improve, you'll never be done that way. Good enough is good enough, hit publish and go on write the next thing.