You want purpose? You wouldn’t know what to do with it. But, fine, I’ll show you what purpose you may grasp.
You are the mind, consciousness emerged from an intricate mass of cells because said mass survives longer and procreates better with a mind caring for it. You are a shepherd for the flock you ignobly call “body.”
Probably you’re already fulfilling your purpose, then. Or maybe not. But if you are, there’s a delightful side-quest to work on until the flock returns to dust. Someone called it “Procreation in a beautiful medium.”
Get to it.