You've already gotten great advice, I just wanted to say good for you for preparing in advance and being so determined - keep it up!
I've exclusively breastfed all of my newborns (my toddler still does just a bit right before bed), but three of the four (so far) have had short tongues and/or high palates, so it was a very painful first 6-8wks...and, yep, that was with a proper latch checked time and again by a LC. I *personally* had a "seven-minute" (that's what I could bear) per side rule of thumb that I followed when the going was really tough. I have a strong, fast letdown and they all obviously got to the hindmilk in that time as they fattened up and thrived very nicely...and it made it doable for me. Once their mouths 'grew into' my breasts, it was just great! I love breastfeeding!
I don't tend to pump (Medela) early on, but, FWIW, I almost never get more than a few ounces when pumping unless a normal feed is skipped entirely. I'm another on the
nurse, nurse, nurse bandwagon! Non-nutritive nursing (if you can bear it) is good, too. Don't gauge what you're able to pump as the same amount you think your babe's getting; it's usually not accurate. I know it wasn't for me/my babies...at all! I also suggest loading up on the Lansinoh = a lifesaver for me!
GL to you!
P.S. - I've never used it, but a lot of moms swear by Fenugreek to supp. milk supply.