Exactly this! I noticed I have a habit of doing this for everything I "choose" in my life. If I choose to buy X, I go online looking for opinions to validate my decision; if I choose to take Y sport, I do the same; if I feel inclined to belive in Z theory or follow W philosophy, I do the same.

I know what I want and believe, but I still find it hard to just trust myself and dive into it, rather I have to always justify it to myself by means of external opinions.

This may not be the best place to ask, but do you have any idea on how to deal with this "lack of confidence in my own choices"?