Preparation has a purpose.
Overthinking keeps going after the useful work is done.

If you’ve gathered the information, considered the realistic possibilities, and decided what you can do, another round of thinking may not be preparing you anymore.

Ask yourself: What am I trying to prevent by thinking this through one more time?

Sometimes the answer is being surprised.
Regretting the decision.
Feeling embarrassed.
Getting hurt.
Making a mistake.

That changes the question.
You may not need a better plan.
You may be asking your mind to guarantee an outcome it cannot guarantee.
Prepare for what you reasonably can.
Then notice when preparation quietly turns into an attempt to control the future.