Dandruff is a layman's term encompassing a number of dermatological conditions, which have you been diagnosed with? Self treating based on a self diagnosis can easily worsen problems by further damaging the skin barrier or increasing irritation.

There are a couple of types of T-Gel effective in mild seborrhoeic dermatitis and mild psoriasis respectively, sulphate surfactants are likely to worsen atopic eczema, irritant contact dermatitis and allergic contact dermatitis, also possibly SD.
2a-2c, medium texture, porous/ colour treated. Three years CG. Past bra strap length heading for waist.

CO-wash: Inecto coconut/ Elvive Volume Collagen
Treatments: Komaza Care Matani, coconut/ sweet almond oils, Hairveda Sitrinillah
Leave in: Fructis Sleek & Shine (old), Gliss Ultimate Volume, various Elvive
Styler: Umberto Giannini jelly, Boots Essentials gel
Flour sack towel, pixie diffuse or air dry.
Experimenting with: benign neglect