OP I have had 3 GAs in the last year. Honestly, nothing to worry about. I actually wasn't scared about them, but they sit you down with an anaesthetist beforehand who goes through your med history and answers any questions v thoroughly.
Then they get you changed and you have to wear lovely fetching support stockings to stop you getting DVT. I recommend bringing a book as there is a lot of waiting at that point, in my hospital anyhow. I brought something light to take my mind off waiting.
Then you go through and climb up onto a bed/ gurney. You have a blanket over you, so it feels pretty secure. They inject an analgesic (painkiller) into one hand and put a drip in. When you have the analgesic everything goes a bit spinny, but in a nice way. When that happens, they get you to breathe into an oxygen mask and the world 'stabilizes' a bit. Then they put the actual GA drug through the drip and you're out in seconds.
In my hosp they have you facing a clock when you go to sleep and another when you wake up, so you feel 'oriented'. I liked that.
The first thing they say to you when you wake up is 'You've had the surgery'. So that helps too.
Also, I was worried about having horrible dreams. I am quite unusual and I did dream or have some type of awareness during the GA. But it was fine, not nasty at all, just some type of sensation of time passing and voices and then I woke up. Bit like having a 'morning dream'.
hth