Double check the cones issue - I am pretty sure PM The Detangler has cones. My hair was incredibly tangly pre-cg, and I think it was from layering of cones.
Have you tried a clarifying wash then doing a DT?
Maybe you don' have to cut out ALL protein, just cut BACK?
Idk... I'm stumped, too!! Your hair sounds somewhat similar to mine (except I'm highly porous), but it certainly doesn't behave the same. :/
Good luck! Keep us posted!!
2c/3a/3b, Fine/med, Dense, high porous, & normal elas.
Lo-poo - Renpure Keratin, SMR, Giovanni SaS
clarifying - mix Johnson's H2T with low poo
Co-wash - Suave Nats. clar. or coco.
RO - GVPCB, Ion Eff. Care, TN.
LI - SMR, Cure Care, or RO
Seal - MO or Jojoba
DT - + honey, ACV, & EVOO to SM masque & GVPCB
PT - Gelatin!, CNPF
Styling - FSG, AIF, BRHG, LALS/PS, GF curl spray gel, SM Souffle/Smoothie, LOOB
Oils - MO!, EVOO, jojoba, GSO, SM Elixer, EVCO, VO5 Hairdressing