When my son was born, his latch was a bit off and I got cracked nipples. I could not see them well at first, but once the LC pointed them out to me, I could. Also I found out that it only takes one bad latch to crack your nipples. Mine eventually healed up, they were not bad cracks so it was good that I got help when I did. (We saw the LC when my son was 6 days old.)
Since then, I have had cracked nipples a few times. I have always had to watch his latch, and when he started getting teeth, his latch changed a little bit again. But at least I knew what the problem was and knew what to do about it.
My LC recommended polysporin ointment on them a couple of times a day, and Lansinoh lanolin after each feeding. Within a couple of days they were feeling much better.