Hun, im so sorry to hear this. But I agree with Rbella, you will be completely ok! Whatever it is, it was diagnosed, and the surgery will make you feel only better. Its good you gonna have it, cmon! You will most likely feel way better after it. I can imagine how scared you are, but everything will be ok.
As for IV or complete anestesia - last summer when i was having a surgery on my nose i was very scared of anestesia. They put me not through IV, but through that complete anestesia with intubation and tube in my throat breathing for me for 1,5 hours, and they made me knock out completely. I was seriously worried about this so much. But the anestologist told me that the surgery goes the way you imagine it to go. You gotta go there and say "I gonna be VERY ok. My anestesia will be easy. My surgery will go good". He said, your mood is 51% of operation. And that was an old specialist who did lots of surgeries so he knew for sure!
I was afraid of feeling sick after i wake up, but it went really good. I wasnt sick at all after that a serious anestesia, no feeling sick, no headache, just was freezing a little. And keep in mind im not the healtiest person ever and i was known to fain a few times and chicken out.
Everything will be ok and you will be finally HEALTHY! You can pm me anytime aswell, and we are always here for you and sending you positive vibes.