I know you have all the good advice you need, but i'm going to post anyway just to give you even more reassurance.

I had major and minor surgery whislt breastfeeding and had the most amazing anaesthetist (for 1 op) who made it his sole purpose to ensure i could bf as soon as i woke up. He said that i might not feel up to it though, (and that's ok), but he'd make sure I had no unnecessary drugs in me.

Please please talk to the anaesthetist before hand. If they aren't sure (some aren't 100% bf savvy) then get them to do some research.

Keep up the good work and don't go into it thinking that 'she's going to go on formula'. You'll be great, and back bfing in no time.

All the best with the op xx