Clobetasol for Psoriasis

I am 22 and have had severe psoriasis for two years and mild psoriasis for ten years.
I found little relief with Dovonex after using it twice a day for a year.
My dermatologist has now prescribed me Clobetasol and I have been using it once a day for two weeks. It cleared my scalp psoriasis in a week! However, the clobetasol cream for my legs seems to be doing the opposite. I'm not sure if this is because I stopped taking Dovonex, but the patches seem thicker now.  

My questions are:
What is the difference between the scalp lotion and the cream (for clobetasol) and is it a bad idea to try the lotion on my legs?  How long does it take for Clobetasol to work?

I had a bad experience with Desonide and was sick for a year with symptoms of adrenal fatigue and hormonal imbalance.  Now, I am having severe headaches, hotflashes, and stomach discomfort.  Could this be related to the newly introduced corticosteroid treatment?  Can adverse side effects happen this quickly?

Thanks for your time.  I could really use some advice.