Hye, you are having severe type of seborrheic dermatitis, you do tar containing shampoo on daily base for one week then twice week for one month. Apply steroid plus salysalic acid lotion daily at night till cure.
Avoid tension. Take proper sleep. Have healthy food.

Hi ,Thanks for posting your query
Scalp psoriais can be mild with only scaling or severe having symptoms like
Reddish plaques,Silvery-white scales,Dandruff-like flaking,Dry scalp,Itching,Burning sensation ,soreness,Hair loss

scalp psoriasis itself is not the cause of hair loss, frequent or intense scratching, forceful removal of scales, harsh treatments, and associated stress can cause temporary hair loss. Fortunately, hair usually regrows after the psoriasis lesions clear.

So you need not worry .Although scalp psoriasis can't be cured, there are many treatments available that can help relieve symptoms, control flare-ups, and prevent recurrences
Following treatment may help:
Anathralin,
Antimicrobials, which are used to treat bacterial or yeast infections associated with scalp psoriasis
Calcipotriene, a vitamin D derivative
topical steroids
Tazarotene, a vitamin A derivative
Oral medications and newer biologic agents are also available

once it is under control ,you may be able to prevent recurrences by shampooing daily or twice-weekly with a shampoo containing coal tar.

So you can contact your doctor , and start treatment under his prescription

Hope this helps you