Hi Cheri. It is very normal to get cold feet and want to back out. It's been a long time coming and now the reality is setting in. Hang in there. This is something you're doing that is positive for yourself. Most of us need to whip ourselves into shape for our health and that's a lifesaver. My surgery is Dec 5 and I'm fretting also but looking forward to it finally. It took a long time in coming. Read others profiles and blogs and see how happy they were after the surgery and how much progress they've made. The Dear Lord is beside you along with all of us here on the website. Keep an optomistic attitude and you'll be fine.
Good luck and keep in touch.