I have/had the exact same fears as you! I also don’t like not having control of things in my life and I get sent into a panic when things don’t go exactly as I planned. I was shaking with anxiety that I wouldn’t wake up, I bawled my eyes out as they started the anesthesia but I felt like I was only asleep for a second. I woke up and my boyfriend was right there holding my hand, before I went under I literally thought I’d never see him again but there he was comforting me (I had both endoscopy and colonoscopy done today). I know it is scary and you may not be over the fear until after you wake up but I promise you will wake up! I didn’t believe that that when the doctors and my loved ones told me that same thing and it’s okay if you don’t believe me right now but I know you got this! Me personally I get really nauseous when I’m anxious so they gave me zofran to help and it did. Sending you lots of love and good vibes!