Gee, Bill...You're a worse patient than I am! And there are asterisks all over my medical records (*this one has opinions...*questions authority...*may bite...).
The recliner will be an enormous help to your sleeping. The hospital beds and chairs become a body-ache nightmare after a while.
Heck, just being home is much better.
Be aware that there is a bodily defense that may make you suddenly take a deep breath and feel, for lack of a better term, terrified that you're not breathing or stopped unknowingly. I have seen it described as and attributed to many different things, even a yawn response (I don't agree).
My own belief is that from the deep anesthesia, the stoppage of your lungs and heart, and the hypothermia used during the procedure, your agonal breathing reflex becomes activated. It shows up at unexpected times, along with a flush of adrenaline the body hopes will rouse you back to life (which you would well interpret as a sudden shot of terror). Of course your body is still alive, but your sats may be slightly down or some other trigger gets it activated. Whatever you attribute it to, it does dissipate over time.
It's entirely normal to be completely preoccupied with your heart and body and recuperation after OHS. We become too keenly aware of our heartbeats, inevitable palpitations, and bizarre bodily reactions that result from the surgery.
There are a lot of very individualized pains and issues that occur due to the surgery, and more that unfold as teh heart remodels (returns to its normal size and function levels). Blood pressure will roller-coaster for a few months. Palpitations will come and go, as the shrinking left ventricle gets occasionally out of sync with the rest of the heart muscle in contraction speeds. It also adjusts permanently over time to any atrial enlargements that don't resolve (it's not uncommon for the atrium not to shrink back all the way), and that can cause temporary palpitations. The reart rate is often high, and a beta clocker may be used to bring it down.
The key to much of this is its temporary nature. Obviously, if you're having a painful or scary arrhythmia, you may wish to visit the doctor or the ER. But if it's just minor flutters, it's likely just temporary. The first week or weeks, you may have low, childlike blood pressure. Then it may go to high blood pressure for a few weeks. Again, if it's at a level of concern, go to the doctor or even ER. However, if it's high, but within reasonable range, it's best not to throw drugs at it right away, because it's likely temporary.
You are well-researched, and that can be a big help to you in dealing with these issues, avoiding medical mistakes, and armchairing diagnoses and treatment options. Unfortunately, knowledge can be problematic when we are tied to psyches that are too aware, too conscious of each nuance of our healing, and we are aware of too many possibilities of things that can go wrong. And OHS creates some of that psyche in all of us (again, hopefully temporarily).
You seem to be recouperating well. It's just tough to walk that line between vigilance and acceptance.
Best wishes,