You can let the answer be simple.
Overthinking is not always a search for more information; sometimes it is a search for a more comfortable answer.
Where this shows up
You may be mistaking repetition for depth.
That is usually the moment worth noticing. The point is not to judge yourself for the reaction. The point is to recognize what the reaction is asking you to see.
Try this today
Ask whether another hour of thinking is likely to produce information or only repetition.
A question worth sitting with
If the answer stayed the same tomorrow, what would you need to accept?
You do not need an immediate answer. A good question can stay useful long after the first reaction passes.
Take this with you
The goal is not the perfect response. It is a response that reflects what you know now.