Suggest Medication To Stop Severe Itching On Skin

I am 35 years old have thyroid (overactive) and under active adrenal gland I take 0.1mg fludrocortisone, 175mcg synthroid,5mg hydrocortisone the problem is my skin is so dry and itches all the time I am black and blue from itching I have tried everything on my skin and nothing works it is unbearable what can I use to stop itching is my medication causing my skin to be so dry it doesn't matter if it is winter or summer ( winter does seem to be worse)