Sounds like you're doing great K, you've been given great advice - I'd just add make sure you're using paper backed breast pads (johnstons, tommy tippee, lasinoh are all good) or re-usables, don't go for the one with plastic backs as they don't let your boobs air and can lead to infections if you are going to be prone to anything.
If your nipples are sore it could be that the latch isn't right and a bit of your boobs adjusting to Lucy's suckling.
Olivia was a snack feeder too and had to try putting a wet cloth on her face and blowing in her face to wake her up a bit.
I have a Coorie sling from
www.brightsparkslings.co.uk and breastfed well in it