Having an upper endoscopy done. Scared of being sedated.?

I have acid reflux and IBS. I have been having some abdominal pains so they are doing an endoscopy to make sure that the IBS and acid reflux are the cause of these pains and not something else. I am 27 years old. I have been put to sleep to have my wisdom teeth removed and for a colonoscopy a few years ago. I do not know what they used for those procedures. I paniced back then but not as bad as I am panicing now, as my panic attacks have gotten a lot worse over the last couple years. I have a huge HUGE fear of death and I am terrified of being put to sleep because I am SO soo scared I won't wake up. I do not know what exactly they are using to put me to sleep, I have looked up the common meds, and I plan to call tomorrow and find out the exact meds they are using. I just really worry about going to sleep and not waking up from it, I can not get it out of my head. Please people that have had an endoscopy done or people that know about sedatives, please help me feel a little better.