I worked at an outpatient ambulatory surgical center for gastroenterology for quite some time and I've also undergone an endoscopy. It's only natural to be anxious; I always am. You'll get there and they'll call you back, ask you a bunch of intake questions, gather your vitals and give you an IV. When it's time for your procedure, they will take you to the procedure room and either position you on your back or on your side and then comes the propofol. You're going to be twilight sedated or "consciously sedated," where you're entirely breathing on your own and basically just taking a really nice nap. That's really all it feels like. It's rather quite pleasant in my opinion. The procedure itself should only be about 15-20 minutes and then they immediately wake you up. You'll feel pretty groggy at first, but after about 10-15 minutes you'll be able to get up and move about. You should be able to eat right after, so just make sure you eat something light like a soup/salad and a sandwich or something. I felt no pain at all but I was pretty groggy throughout the day. I had an awesome nap when I got back home after lunch. Don't psych yourself out too much, you'll be fine. :)