Psoriasis in, behind, around ears and slowly moving onto my scalp

So my ears started to itch and scale when I was around 15, I went to the doctor and was originally mis-diagnosed as having eczema and given some kind of thick, greasy paste to clear it up. It took a good 4 years or so before another doctor noticed the worsening scales and asked why my psoriasis wasn't mentioned in my medical records. I'm 23 now and the psoriasis around my ears has never really cleared completely, a few months back I was prescribed a steroid cream of some form and told to put it on sparingly before bed. If i use it every night for a few days to a week it does clear up my ears but within two or three days it's back with a vengeance, covering my ears and surrounding neck area with thick, dry, splitting scales flake off all over the place and generally make my life miserable. I've noticed on top of that, the psoriasis has begun moving into my hair the last month or so which leaves me with an unbelievably itchy scalp at all times. I am desperately trying to find a way to treat this newly developed P and I don't know what to do, I have very long hair (hangs down just past my waist) and this itchy scalp is driving me insane! I find myself constantly finding huge flakes of the stuff sitting in my hair, getting all over my clothes, the furniture and everything else I go near during my day and it's extremely frustrating. Can anyone give me some tips on dealing with scalp psoriasis?