The reason that many of us have trouble coming to grips with the notion that our consciousness is nothing more than the functioning of our brain is related to our underlying dualism. We are unable to believe that consciousness is identical to brain function We think something is left out of that formulation and cannot escape from the debilitating idea that consciousness is something over and above whatever constitutes our normal brain functioning. We begin to look for answers in the ether, in quantum mechanics or we begin to say that consciousness is unexplainable. Let me see if I can make an analogy to the concept of force in physics to try and disabuse you of your dualism.
I got the idea for this analogy from reading Bertrand Russell. Imagine that your car is stuck on the road and you want to push it out of harm's way on to the grass. You put your shoulder to the rear of the car and push as hard as you can. You are applying a force to the back of the car in order to move it off the road. If you think about what you are doing, you cannot help but feel you would be leaving something out by not applying the concept you have called force.
Without force, the car stays put on the roadway. I am repeating myself here to make it absolutely clear in your mind that the force is necessary in order to move the car. That, after all, is the way we all learned Newton's law in high school physics class. No force, no acceleration. But force equals mass times acceleration (f=ma). So force, in physics, is superfluous. We could have left it out and simply used mass and acceleration as our concepts and still would have successfully moved the car off the highway.
But that does not mean that force does not exist, that it is unnecessary to apply force to get the car to move. It means that force is constituted by mass and acceleration. It is made up of these two things and there is nothing above and beyond mass and acceleration that are needed to have force. The same goes for consciousness. Once you have wakefulness and content, you do not need anything else to constitute consciousness, provided that the content is full and correct. There is nothing left out, because there is no extra stuff that is necessary to constitute consciousness, just as there is no extra stuff necessary to constitute force above and beyond mass and acceleration.
It seems to me that the only way to wiggle your way out of accepting this analogy is to say that force, mass and acceleration are all physical but that consciousness is not physical, hence the need for something extra. But that is dualism, and we want to stick to materialism, if we can.