Orbit
I'm a planet
Right there. Your subjective experience of the electrochemical reaction in the brain is irrelevant to everyone but you.
You are committing the sin of reductionism, which is a no-no in the scientific method. You are doing biological determinism. The mind is not the brain. You seem to think physical science is the only science out there. Epistemologies are tools. You wouldn't use a microscope to look at the stars; and you shouldn't try to use an MRI to look at the mind.
Subjectivity is quite real. Pain is subjective and it matters a great deal to you if you are the one in pain. It is not defensible to dismiss all experience on the basis of it being subjective. In addition, meditative states have been well documented, and we do see patterns in the kinds of subjective experiences that people have. If you were being rigorous, you would turn to phenomenology, not physical science, to examine the question of mystical experience.