I have tried countless anti-psoriasis shampoos and still can't find relief. Can you recommend any products?

I have tried Neutrogena T-Gel, Neutrogena T/Sal, and 4 other various organic anti-psoriasis shampoos. I am getting so frustrated with my situation because I can't find relief from flaky, hard patches and itching no matter what I use. Please tell me what has worked for you.