It's completely normal to be nervous, no one wants to have elective surgery. A couple of things really helped me with the temp ostomy, first I looked at it as if it were a science experiment. More than that, though, I tried to put in perspective that the ileostomy gave me my health back immediatly and for that I was grateful. I knew immediatey upon waking from surgery that my UC was gone, no more discomfort in the abdomen. The ileostomy allowed me to start living again, going on walks and hikes; those things were very important to me. Take advantage of an at-home visiting ET nurse, their knowledge, help, and support in dealing with an ostomy is invaluable. I wish you as much success as I had, one day hopefully, your UC will be a distant memory.
I had my temp ostomy for 8 weeks and then had the reversal surgery. You can certainly postpone your second surgery for a long time if you want to reconsider. Be well.