You'll be fine. Your odds are especially good if you've previously had anesthesia without complications. I've been put under a dozen or more times, and I keep coming back. There's always a chance that something will go wrong, but it's infinitesimal. Doctors have gotten really good at safely administering anesthesia. Just insist on meeting the anesthesiologist before you go under. Introduce yourself and make sure he knows he's about to sedate a real person. You'll be great. See you on the other side!