GED1975- I can certainly relate to what you are feeling. I went to the pre-op just for my heart cath today, and all of a sudden, I felt wobbly. I think that it was the CYA things that I had to sign saying that I understand the various and sundry things that could go wrong. Actually, all the nurses who worked with me were wonderful, but up popped the emotional reaction, from out of nowhere.
I sat in the hospital after I was told I could leave, took a Valium, and bought a package of M&Ms. THAT helped!
I think that it is the anxiety of the unknown, which is a perfectly normal human reaction. What I usually try to do when faced with surgery, (of which I have had many) is to focus on the time AFTER the operation.
In a short while it will all be behind you, and you will have a new lease on life.
Take care, and let us know how you are doing!!!