This may be sebopsoriasis. Please send photos using online consult option for proper examination diagnosis and treatment advice.

You can use Salisia KT lotion as shampoo for now. But you need to get your scalp properly examined to know whether the excessive flaking is because of seborrheic dermatitis or an inflammatory condition like psoriasis. What you describe is more likely to be due to seborrheic dermatitis but without examination and confirmation cannot prescribe a more definitive aggressive therapy. Kindly do not delay the treatment and get a consultation done with a qualified dermatologist how are you can get an online consultation privately with pictures if you wish. Hope this is helpful.