Does anyone here ever do it? It's my biggest obstacle when it comes to writing. any advice?

Overanalyzing is a definite problem for me too. The whole 300 words a day and don't sleep until you've written them thing seems to be working pretty well so far.

It depends on what aspects of the material you are over-analyzing.

Here is where my personal opinion may vary from others

If you are constantly asking yourself if a particular paragraph is furthering the story in a meaningful way, if the character development is on pace, if a description is painting the right image, or if a passage conveys the mood you are looking for... then I don't think you can EVER over analyze those things.

However, if you are dragging out the magnifying glass to decided if a puddle of water "reflected the moonlight" or "mirrored the night's luminosity"... then you might be over thinking things.

Words are words, and the truly poetic ones, the ones that will touch a reader, are the ones that found their way to the page effortlessly. I, for one, don't believe words should ever be "found" and then "forced" on the page. A reader can sense that...

Analyzing for content= yes
Analyzing for style= sure, but be careful.