Hair damaged only at nape of neck?! Tried everything?

So the mids to ends of my hair on only the very bottom layer is damaged, dry and crinkly. I stopped all chemical treatments to my hair two years ago, and the rest of my hair is 100x better than before. But this section of my hair no matter what, has stayed damaged. At first I thought it was still growing back from the bleaching I used to do, but its been two years and the bleach is almost completely grown out. I use a satin pillow case, vanicream shampoo, and a pretty good hydrating conditioner. I also use jojoba oil, castor oil, and almond oil in random rotations. I have fine straight hair that is down to my boob area. I occasionally blow dry, a few times a month using heat protectant and try not to overheat any sections. I can use a lot of oils but no shea or cocoa butters. I found an acidic bonding mask I could use and that actually made my hair feel way worse. I am allergic to most products, so I cannot really use most recommendations. What would you think is causing the breakage? I have noticed my hair around my earrings (flat back so they stay in) gets broken but I doubt thats causing all the damage. I get regular trims, and I also go through and snip split ends multiple times a month. I want pretty healthy hair. 90% of my hair is nice, but the rest is a DISASTER and I don't know what else to do, that I am not already doing. TIA <3