Orthodontist

I went to the orthodontist today. I need to get braces but I never knew my teeth were this bad. In order for me to get braces, I need to get jaw surgery. If I don't get this done, When I grow up my jaw will get pains all the time. I'm worried about getting the surgery because I have never gotten a surgery done on me and I'm afraid that they will dislocate my jaw into a really weird place or just mess it up. I'm scared that when they do it, I will wake up (they will put me to sleep but i'm scared that i will wake up during the surgery).