I first came across zen Buddhism when I was 20. I was so influenced by it because it opened up my mind in many ways.
Zen doesn’t impose any beliefs on you. Every religion wants you to believe things, god, rituals, this, that…But zen instantly makes you feel free because you don’t have to believe anything. It is not a religion, a theory, or a philosophy. It is a way of life.
There are no rules in zen. The aim of zen is to point directly to the true nature of existence, and the true nature of your mind. That is why I still keep going back to zen.
Also check out this short video on dealing with overthinking by the way of detachment.