Oddly, that calm may well follow you all the way into surgery. I never decided if it was from finally releasing the responsibility to the doctors, a transcending, zen-like personal acceptance, or just deer-in-the-headlights syndrome, but it is a weird, calm, detached, and good place to be in your head for tomorrow.
You will be in my thoughts tomorrow, as you go through your procedures. We do know what you're going through, and with so many of us thinking of you, it seems impossible that you could ever be quite alone through this.
I wish you well,