I think we've inherited a sense of BFing being a black and white thing. Either you're the human equivalent to a dairy cow with nipples of steel, or you can't do it because you don't 'have enough milk' which is why the baby cries. You still get a bit of this from HVs
.
In reality it's a complex picture and I absolutely agree with others who've said that you should have a realistic attitude.
It's hard to begin with for a lot of women (I'd go as far as saying for most women). But this is for a variety of reasons - tongue tie, colick, reflux, baby struggling to latch, you struggling to teach your baby to latch, getting your head round the relentlessness of it in the early days. Mostly though issues are solvable.
Most people will have an issue with something and really it's a case of keeping going, getting help, and knowing that it will in all likelihood get better as the baby gets older. Once you get through the early days it's generally dead easy, and really convenient.
Both of my DC were fed until they were about 14 months. In the case of DS, he struggled to latch on, I had mastitis, very sore nipples, and despite feeding for a long time was a slow gainer. He was also colicky. I think probably he had a tongue-tie but I got very little support and just ploughed on ignoring the 'you need to top up with formula' brigade, because I was convinced I just needed to get used to it. To be fair I did, and it ended up being a very rewarding experience, but bloody hell I wish I'd had help!
With DD I was very confident, sure I'd be able to feed her, almost a bit complacent. That meant that I was a bit relaxed about the whole thing to begin with and ended up with very sore nipples for a while. Absolutely my own fault for forgetting that newborns have small mouths and you need to learn together how to do it. It got better of course quite quickly but it just goes to show, it's absolutely not like learning to ride a bike.
Anyway, good luck whatever you do.