Terrified of what lies ahead!

As others have said @CathyMac try focusing on the fact that you are taking control and acting - getting that cancer out of your body.  At the hospital where I had my surgery, they had small balconies off each room with the doors firmly locked.  I can remember joking (or trying) to my surgeon that it was really so we couldn't escape while we were waiting to be taken down to surgery.  I was positive but very anxious - it's normal and if you can be given something for the anxiety, take it.  When the anaesthetist was putting the drugs in one arm ready for surgery, my surgeon was holding the other to reassure me (apparently, it's normal practice for him).

You will get through this.