Could nizoral be making things worse?

Can't tell if I'm using it too often and drying out my scalp, or if I'm just entering into a worse than usual flare up. I use the Nizoral psoriasis shampoo 1 to 2 times a week. Been doing this for several months now with no previous issues. The itchiness is driving me nuts and my clobetasol isn't helping 🙃