There is a time for thinking and a time for doing
How often have I found myself in front of my computer, a bunch of windows opened, not knowing what to do, paralyzed by too much Overthinking kills momentum and analysis. That's because I mixed thinking with doing.
Thinking time should be done as an activity in itself, completely focused, not doing anything else that requires concentration. It's not coincidence the greatest thinkers did their thinking while walking, sitting, or in the shower. It's also Why you are full of ideas and drive at night. Sit down or take a walk, and dedicate some time to thinking, and just that. No phone, no talk. Spend some time alone with your thoughts. Spend time in reflection every day.
Thinking—and reflecting—will help you assess if your actions are aligned with your values, and truly understand why you are doing things. It will help you remember why exactly you are doing things, and keep your expectations aligned with reality.
Then, when it's time to act, switch gears. It's not the time to think hard anymore. Let the momentum build and flow with it. Thinking while in the action will only bring doubt, second-guessing, and paralysis by analysis.
When you decide to act, do it in a steady, deliberate way. Take your time, going slowly to focus on the process. Surrender to the action.
Finally, after having taken action, spend some more time on reflection.
In essence, Act fast, then take the time to reflect.