While I've never had back surgery, I've had major surgery in 2006 for lung cancer. Never once did I worry about it as I had put 100% faith in my surgeon whom I met many times before the surgery date.
The one thing I learned was to not waste energy worrying needlessly. Instead, pre-surgery, I focussed on being as healthy as I could be at the time so that post-surgery recovery would be much faster.
Breathe deeply and know that everything will go well. I have it from the source, Merlin. He tells me that you will be surprised on how well you do.
Life should NOT be a journey to the grave with the intention of arriving safely in an attractive and well preserved body, but rather to skid in sideways, champagne in one hand and strawberries in the other, body thoroughly used up, totally worn out, and screaming WOO HOO - What a Ride!
Sometimes the most real things in the world are the things we can't see
Until one has loved an animal, part of their soul remains unawakened.