Re: Switching from pump to breast
Is 8 weeks the babies' corrected age, or just the number of weeks since they've been born? If they're 8 weeks corrected, then you're probably in a better place to transition to exclusive nursing.
The way to transition to exclusive nursing is to have babies who are ready to do it, and to have a milk supply that is pretty closely matched to their needs. It sounds like one baby is probably ready to make the transition- that's the one with a painless latch, who is simply a slow feeder. The one with a painful latch probably isn't ready yet, because a painful latch is often a latch that isn't very good at extracting milk from mom.
You're 16 oz shy of what your babies consume in a day, which is a fairly significant shortfall. Does that mean your babies each get about 8 oz of formula per day? If so, then that implies that you need to keep up with the pumping for a little longer, while your babies get bigger and stronger and figure nursing out, and figure out how to nurse well enough to boost your supply on their own. I know that nursing AND pumping AND caring for newborn twins AND a 3 year-old has to be exhausting... But the supply = demand equation that governs milk supply just doesn't care. Which sucks, because it would be great if busy, tired moms could get some sort of a break!
Your babies are eating every 3 hours. How much are they eating at a time, and are they mostly nursing or mostly getting bottles? Nursing just 8 times a day is very uncommon for 8 week-old babies, and even more uncommon for 2 week old babies (still not sure what your babies' corrected age is). Most young babies nurse quite a bit more often than that, so I think that you might want to put them to the breast every 1-2 hours during the day and see if that helps them get better at nursing, and helps your milk supply come up.
I'm sorry if it seems like I am telling you to "just" work harder, when I am sure you are maxed out!
Coolest thing my big girl said recently: "How can you tell the world is moving when you are standing on it?"
Coolest thing my little girl sang recently: "I love dat one-two pupples!"