Talk to Dermatologist on Hairfall

I have oily scalp with extreme dandruff and hairfall issue. It is not due to any specific reason but due to using chemicals based shampoos and due to nutrition deficiency. In addition to this, there's no new growth of hairs as it seems to me like my hair length is still from my last hair cut 6 months back. Plz recommend me a good shampoo for controlling oil production and reduction of dandruff and any serum for stopping hairfall and for hair growth.