On top of fear of looking stupid, my bigger concern is lack of novelty in my work. Seems like any idea I have for a blog post or book, or any photo I'm planning has already been explored in depths by someone else. I know the joy is in the process mostly, not the result. But doing something while knowing it is certainly not original make it really hard.
You shouldn't disregard that even when you have the same intent as someone else, you work your way to get there, and that's usually more than enough to build a distinction.
It probably has. It's super difficult to be truly unique in a world where billions have learned to read and write. It doesn't matter however. The people who see your work haven't seen/read everything out there. You can be unique for them.