Sore nipple help

I'm on day 3 of breastfeeding my newborn. My transitional milk is starting to come in and my boobs are getting fuller. And omg are they sore!! and so are my nipples!! I feed him every 2-3 hours unless he cues me to feed sooner. I've been told by multiple nurses and Drs during our hosptial stay that he has a good latch, but today my nipples feel like they are on fire especially at the beginning of a feed, then it stops hurting, until about 20 minutes later the fire starts up again. and my left nipple is a little cracked. I use lanolin after each feed but is this normal? any advice?