Fine, 3a, high porous, as well.
I would steer clear of mag sulf right now, just until you get your build-up managed, and get the protein/moisture balance back in line.
I would clarify, perhaps try an ACV rinse, and then do a PT/DT.
My hair LOOOVES protein, and my porous hair has never been better than when I started sealing with mineral oil! You might give it a try - there is a thread about it.
Product wise I'd suggest anything by Shea Moisture, GVP Condistioning Balm, co-washing when possible.
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