I was on the "calm" end of the scale. Of course, I spent over 9 years in The Waiting Room, so I had lots of time to accept what was to be. My approach was to put all of the energy and anxiety into developing my plan for surgery and post-op recovery. Then all I had to do was to "work" the plan. I had my schedule plotted onto a calendar, showing all of the tests, doctor visits and other milestones, right up until (and inlcluding) reporting to the hospital the morning of my surgery. Once I had my plan on paper, I could let it go. I didn't have to worry about whether I could remember all my meds, appointments or test results. I had it worked out. All of the decisions were made. I had chosen my hospital, my surgeon, my cardiologist, which valve I preferred, what surgical procedure would be my choice -- it was all decided. All I had to do was to get onto the train and ride it out. I went to the hospital and through the pre-op process with hardly a quiver. Calm, almost surrealistically so.
So, my advice to you is to prepare your plan, then just work the plan and stop worrying about everything. Once the decisions are made, there really isn't anything you can do anymore to affect the outcome, so just sit back and enjoy the ride.