I had some pretty bad nipple trauma, I kept using the lansinoh gel before and after feeds and if there was a gap between feedings like more than an hour would apply to keep it moist, also improving my latch has helped heal it. I've heard some people use these nipple cups that u fill up with breastmilk and apply to nipples between feeds, they bit more expensive tho £20-30 so I wasn't able to explore that option but I've heard others rate them well
I've found silver nipple cups amazing, especially in early days. I have the livella brand from amazon, they are £30. Some are more like £50, I wouldn't spend that much, mine have been brilliant, on baby 3 with them now. No idea how they work but seem to, like Amanda says you express a bit of breast milk into them.
Another vote for silverettes! My nipples are healed now but when they were awful, silver cups saved me. Genuinely think without them I would of packed trying to breastfeed in
My 1st had a tongue tie which we paid privately to be snipped as he was hitting the milestones the HV & GP wasn’t interested, the pain to feed him was toe curling until the tongue tie was sorted. I found pumping & feeding via a bottle allowed my nipples time to heal from some of the bruising. Could this be an option for you? Have you tried different feeding positions to see if that improves the latch & help with the trauma?