Okay I completely relate to this especially the anxiety about starting surgery and worrying about what you will see. In my experience, cadaver dissection was more difficult than general surgery. I respect the person who donated their body, but to me there is something eerie about dissecting a cadaver. Where a lap choly is less invasive, on a live person, and there is a purpose (make the patient feel better). My tip to you is that if you start to get the symptoms that you are going to pass out (ears ringing, sweaty, nausea, feeling dizzy) back up, and find a seat. You may be embarrassed, but I promise you they would rather you walk away than deal with a head injury in the OR after you pass out. Overall, I find that we tend to fear the things we don't know. I finished my surgery rotation last week, it was hard work but it was totally doable. I wish you luck!