Overthinking means unproductive thinking. I don’t like the term
“overthinking” because it implies, incorrectly, that a certain amount
of thinking is the right amount (what amount? never specified) and to
go above or below it is irrational. This is no help at all. Sometimes
people who are threatened by what you think, even if you have a good
point or ask a valid question, will tell you not to overthink. This is
dishonest on their part and you need to be careful. However, there IS
such a thing as nonproductive thinking. Here are some of the
characteristics of nonproductive thinking:

1) Thinking the same thing over and over again, without attempting to reach a solution;

2) Thinking that does not lead to a solution, or at least closer to one;

3) Thinking that paints you as a helpless victim without integrating in what you DO have control over;

4) Thinking without reference to action, or thinking never followed
up with action (even experimental action, to see what’s true and what