Sore nipples

I’m looking for so advice from people that have a lot more experience at this than I do. My baby girl and I have been exclusively breastfeeding since day 1, we are 16 days in now and my nipples are still sore! They are pink and super sensitive to touch and water. They have recently began to itch. Now they aren’t cracked or bleeding, just pink and sore. I’ve been thinking the problem is the fact that I have small nipples. In the hospital we had difficulty with latching at first because my nipples are small. We tried the shield but she didn’t like that either. Eventually she started latching and we didn’t have any issues. It doesn’t hurt when I breastfeed at all, they are just sore after. My LO is getting plenty of food (gained over 10oz in 6 days! Pediatrician was shocked). I’ve been using boob ease cream I got off amazon on them and it helps but I thought by now this pain would subside. The pain is mild but enough to where I’m definitely feeling them be bothersome throughout the day. Everything I read online says it’s a latch issue but I just don’t think that’s the case. Anyone have any advice to why they are sore? Will they always be like this? I’m worried it’s because my nipples are small and she has to suck them so big every time she feeds.