Definitely go to a doctor, better safe than sorry.
I also had very dry hair until I accepted that I had hard water (no more co-washing always had a gunky scalp from it anyway) and went back to sulfate shampoo that is protein & cone free (Sauve Naturals green apple along with the condish).
If you haven't already give Kinky Curl products a try, they are rich but don't weigh hair down & Protein-free. Skip the heavy oils for a bit, for LPorosity they leave you w/straw dry hair.

Back on the CG wagon!
Hair Type: 2c/3a winter, low porosity, protein sensitive
(Cleanse w/Distilled water only)
Shampoo: Baking soda & brown sugar
Condish: Sauve Naturals green apple or aloe waterlily
Rinse: ACV
LI: Kinky Curly Knot Today
Styler: homemade flaxseed gel, topped w/KC Spiral Spritz
DT: veg. glycerin mixed w/conditioner
"Life's a garden. Dig it."