Insane anxiety about getting a colonoscopy, unbearable

I'm scheduled to have a colonoscopy this upcoming Monday and I have been petrified about the whole thing coming up, I want to cancel or reschedule so bad because the anxiety is making me go insane. I'm terrified of the prep, I have to dri k a big ass gallon of prep, 3/4ths the night before and the rest the day of the exam. I'm so worried I'm going to be nauseous and vomit all over and not be able to stop and will have to go to the hospital for dehydration. If I somehow survive that, I am terrified of the sedation. I've only been sedated 1 other time and that was 14 years ago for wisdom teeth removal and I didn't have anxiety back then. Im worried about having a panic attack while sitting there waiting to get sedated and worried about waking up in a panic attack during the exam itself. Then lastly, of course, I'm terrified of them finding out I have cancer. No doctor has been concerned with my symptoms up until this point but I have been concerned myself, so they just said for peace of mind, do the colonoscopy. I know it sounds super stupid and silly, but this is the worst my anxiety has been around any sort of procedure, it feels like so many things can and will go wrong. I honestly don't know if I can go through with it.