Every month i get this scab like dandruff in my hair yet when i brush my hair it bleeds, what do i do and what is this?

Scalp infection: Infected seborrheic dermatitius with impetigo- get seen and treated with topical and oral antibiotics.

Seb Derm / Psoriasis: Ur condition could be due to seborrheic dermatitis or psoriasis. Both can cause the symptoms u describe, but treatment is different. U can try Nizoral (ketoconazole) shampoo 2-3 x/week as directed, and either Selsun Blue or Head & Shoulders intensive treatment the other days. If no improvement w/i next 2+ weeks, see a clinician to determine if u have psoriasis, which requires topical steroid/tar treatments.