There's a fine line between reflection, and whining. Usually, when I put a more esoteric question up for such a discussion, I seek for advice, not to vent.
So, I am really good at what I do, at least most of the time. Now, I have found that I generally tend to work slower than I'd like to. Usually to good results, but I tend to put too much thoughts into things. I feel like this is something that inhibits me from being more productive. - Yet, and I am not sure how to phrase this in English, this slowness has become ingrained in my working habit. So, what do? How can I work fastre, yet preserve my diligence in my approach?
Sounds like you need to do a couple of things. First, focus on the large issue at hand, not the minutae of the process (unless that's your job). Second, one thing I've found is that a lot of projects have common requirements, that are documented or done in the same way, for every project. If your job requires written results, often setting up a "Pony" documents file in your word processor or other computer program will save you a ton of time on projects. You do have to make sure your "ponies" are current, but they generally don't change too much or too often.
It might depend on the type of work. You're meticulous. Can you make your next challenge to be meticulous something like "work faster yet preserve diligence?"
You make me think of "motion study," which is the management practice of analyzing what actions you do to accomplish a task, and find a way to do the same task with less motion. Things like "make a batch file and run it rather than type in the commands every time" and "move the raw materials and the table you're working on next to each other rather than making trips across the room."