Find a hairdresser older than you are.
Jam - I have nothing new to add really. Can only reiterate that second labours and births are so different to the first. Apart from anything else, your body remembers what it's doing. With S I had a 16 hour labour, back to back baby and an epidural and with A I had a 5 hour labour at home, no drugs and a water birth. The main differences was that with #1, I was in a hospital being "told" what to do and was feeling "medicalised" by being in hospital in the first place. Also being young and not realising that I even had a say in it. With #'s 2 and 3, I was in a comfortable environment and just did what felt right. Even 2 and 3 were different. With A I spent my labour rocking on my hands and knees, with O I got into that position and instantly "knew" it felt wrong, but sitting on the birthing ball with legs wide apart and leaning into DH felt right. I was listening to myself and it worked and I'm sure it's because I knew I'd done it before (albeit with an epidural), but I had still pushed a baby out before, as have you.
I'm lucky, I still had a pretty good experience the first time, but that was luck. The other times I was more "empowered". Bit of a yuk word, but it's true. In fact, I was most in control with A, having done the hypnobirthing classes beforehand. Worth considering, even at this late stage.
I think going and talking to a midwife at the birthing centre is a great idea. I really think you'll feel so much better.
SOH - I would be horrified if any surgeon agreed to it so soon after a traumatic birth experience, sorry. You're only just coming to terms with that. I think you need to give yourself more time before embarking on a life changing decision like that. I know you're an intelligent, grown woman who is perfectly capable of knowing her own mind, but I worry so much that you could change your mind in a couple of years. For example, if you're home schooling M, you might start to think that she'd really benefit from having a sibling around. You never know. G&T - with her 7th on the way, you can pretty much see where she's coming from!
Hope you don't mind me saying that. It's an op that really worries me. And besides, if anyone is going to do it, it should be DH. Simple op, fewer possible complications and usually reversible.