First of all, I'm really, really sorry. SO sorry.
The main thing I learned from all this is that there are some things where you're truly on your own. Nursing is one of them. There's probably little advice you haven't already heard or read or hunted down like a madwoman, so I won't add to that roar.
All I've got is: whatever happens, it's OK. Your baby will be OK. No one but you can survive or not survive Boob Hell for the two of you. I survived, but I don't know how and I don't feel like I deserve any credit for it. If you don't survive, I understand, and so does any other reasonable person who's been to Boob Hell. Anybody who makes you feel bad about it is a jerk. Try to be nice to her because she doesn't know that you already feel more than bad enough without her help.
Vaya con Dios. I hope you make it, and I get it if you don't. Whatever happens, I would still totally be your friend if I knew you, unless you're a psycho in some other way.