1) it doesn't exist, but our brains are thinking and talking about it
2) it exists, but it's overdetermined: it just so happens that your brain starts thinking and talking about it while it also exists
3) it exists as a phenomenon in the physical world, able to affect other physical things
As I said, I don’t know. I agree it’s not clear.
The first book I read on the subject, many years ago, was “Body and Mind”, by Keith Campbell. The book outlines various positions taken on the mind problem. I still have the book. Your position appears to be a version of epiphenominalism.
I found the book helpful as a short overview of the subject. For example, in chapter two the book describes the mind-body problem as four propositions that form an inconsistent tetrad. Any three are mutually consistent and can all be true. But any three together imply that the fourth is false.
The four propositions are: (1) The human body is a material thing. (2) The human mind is a spiritual thing. (3) Mind and body interact. (4) Spirit and matter do not interact.
The author describes a “spiritual object” as “one that does not have all the qualities of matter; it lacks at least some of: mass, volume, velocity, solidity”. (Some qualities of matter are allowed, just not all.)
My view is that the universe is a big movie. Consciousness is just a lens through which you get to watch the movie. But the movie script is already written, or being generated by mechanisms out of your control. You just get the immersive experience of the “feeling” of being one of the characters, including the feeling of making each decision—which are being/have been made for you.