It Lives
Do you know where the diaphragm is? It's the muscle right at the bottom of your ribcage, essentially dividing your abodomen from your chest. If you can envision where you would pinpoint the middle of your torso, you get the general idea. That's where the creature lives.
Sometimes it vibrates there, creating and spreading tension from the core of me to my extremities, and I'm perpetually on the edge of something and feeling wrong in a way that is impossible to verbalize.
Sometimes I think that it can stretch itself out. That creature is still in my chest, but thorny tendrils originating from this being make their way up my spinal cord and into the base of my skull. My shoulders tighten and I get the intense and excrutiating feeling that I've done something horrifyingly wrong, and any moment someone I love will come through the nearest doorway having been disappointed by yours truly.
Sometimes it stays put there, surrounded by that diaphragm muscle, but still shifts within its little cage. It will crawl in little circles, restless, it will twist and turn and scrape against my ribs as though it's trying to play percussion, but softly. It doesn't create such an intense sensation for me, but that's the sneaky part. It's just conserving its energy so it can prolong this activity. All. Day. Long. By the time the day is over I want to scratch and scratch at anything I can reach.
Sometimes it will be completely silent and still, but it will become unimaginably heavy. I'll wake up and find myself sunken, as though this thing has compressed my core while simultaneously being the only thing holding my ribcage from meeting my spine. Because of this weight, this new burden I have to carry, every task takes incalculable new levels of energy. Getting out of bed requires a recovery period of unpredictable length.
Sometimes it doesn't do any of these things. I can still feel its presence, but sometimes it just exists. It doesn't stretch, or buzz, or compress itself into the heaviest thing in the universe. At times like this, I imagine it in the little cave that my ribs create, just reading. Or writing, like I do. Instead of a parasite, I think of this creature as a symbiote. Does it know that it hurts me otherwise? I wonder, sometimes, if I could eventually find a way to tell it that this is best.