Why is your scalp red?

Hello! My name is Makayla and I struggle with psoriasis pretty much all over my body. I’ve tried so many products I’ve tried steroid solution- I ended up crying... I’ve tried this injection called humira it worked amazing! But sadly I had to stop it due to a thyroid problem I have developed. Since discovering my thyroid problem my psoriasis has spread crazily.For a while it was mostly just on the lower part of my scalp, in my ears, and on maybe one finger nail. Now it is on five fingernails, all over my scalp, gotten worse in my ears, and has spread to areas we will just say psoriasis shouldnt be at... I’m looking for advice I need it very very bad! Please HELP!!