Agree with Blueblood if your curl pattern had been affected chances are your hair is beyond salvaging and needs to be trimmed, sorry.

Hydrolysed protein can patch repair the surface and strengthen the cortex but it cannot restore the structural bonds that create curl. Coconut oil is useful for increasing elasticity and reducing porosity. Other proven ingredients include ceramides, 18-MEA and panthenol.

Next time you colour run stand tests in shed plug hole hair, don't use your whole head as a laboratory.
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