There a so many things you can worry about, we are all human, I tried to look at what I was gaining, but I was still a big guy going under anaesthetic at the age of 50, I was just happy to wake up in recovery.
Please relax and you'll start to enjoy the journey, the LSD and the post op liquid and sloppy diets aren't fun, but when you look back they weren't for long and they weren't that bad really. Eye on the prize.