Best product for flaky dry scalp?

This won't post on r/skincare or r/hair so I'm trying here.. Sorry

Anyway, I have a mixture of dandruff & psoriasis which is causing severe flaking & itching.. It's making me miserable. If anyone has suggestions for products that work then please share, it would be beyond appreciated!

I currently use Head & Shoulders Dermaxpro Moisture Repair.. It doesn't do the trick