Which meshes with my own confirmation bias: It's mostly about the way people feel about things. Such experiences often don't offer any kind of concrete insight on their own. Instead, they put the person in a frame of mind where they are more open to new ways of looking at things. (Personal experience: I've tried psychedelics myself.)

tbh it doesn't sound like you have a serious confirmation bias; it sounds like you are looking at the evidence trying to build your ideas on firm foundations, and are aware when the foundations aren't firm. That is a healthy cognitive outlook.