There always is a point when something that seems good will become too much of it and change into something that might even be bad.
Doubting oneself is an excellent approach as long as it leads the way into curiosity, learning, collaborating, checking, or whatever is assisting the relationship that the doubt relates to. It can be the relationship with knowing or doing. It can be the relationship with others, life, or the environment.
However, when the doubt disappears or when it becomes overwhelming, the doubt has lost its power to provide support. It becomes focused on right or wrong, good or bad, and sees them as exclusive. What has been lost out of sight is that there never is anything that is entirely right or entirely wrong. It depends on the context or the perspective. What is right for some will not be right for others. When something is good for some, it often will be seen as bad by others.
When something is good, it doesn’t mean that it is perfect.
There is nothing new about this. But the more one’s perception of events or situations is polarized, the harder it is to remember that there might be too little or too much doubt.