I know some essential oils, if left on the skin, can be irritants for some people. Some examples are orange oil and even lavender oil. I would check the ingredient deck on your products and see if there are EOs listed; maybe exclude that product from your routine and see if the irritation goes away.

2c/3a: Fine, Thin, High Porosity; very fragile.

Currently Using:
Weekly LoPoo: ABBA Pure Curls Sulfate Free Shampoo
CoWash Cleansing: Tresemme Naturals or Giovanni TTTT
Condish: CJ Hibiscus & Banana
Leave In: ABBA Pure Gentle w/ Argon Oil added
Stylers: ABBA Pure Style gel (warm temps) or CJ CCCC (cool temps)

Special Stuff:
Coconut Oil scalp massage - Weekly
PT/DT - Kpak Reconstructor / Kpak Intense Hydration (as needed)