Suggest Treatment For Sores On The Legs And Arms

I have sores on my legs and arms. They were also on my stomach, but they have since disappeared, leaving dark spots where they were. When they first came about 3 months ago, my arms and legs were fevered and dry, I went to my family doctor who took a biopsy of one of the sores which came back as an ulcer. I was referred to a dermatologist who said I had stress dermatitis. They are severely extremely itchy, so much so they are interfering with my activities of daily living. At first I would scratch so much in my sleep that I would wake up to what looked like a blood bath. They are still severely itching, but now it wakes me up. I am sleeping maybe 1 hour a night before they wake me up itching. These are sporadic on my arms and legs, no set pattern. They are painful; at times it feels as though someone is stabbing it with a knife. Now I am developing a rash on the upper portion of my right arm. Everything the doctors have given me it seems as though it builds a resistance to it within 3 days to 1 week the product stops working. All I can do now and cry and itch. I have tried Sarna, Cetaphil body wash and cream, Calagel. I have another doctor’s appointment on 03/17, but I am to the point where I feel I should go to the emergency room because I cannot stand the itching. And my skin on my arms is extremely sensitive, if something is barely rubbing against my arm then I start scratching like crazy. Such as I am typing this on my laptop and my wrist are barely touching my pants and they are itching like crazy. I am hesitant to put anything over-the-counter on the open sores unless a pharmacist or doctor recommends it as I am not sure what I should not put on the open sores. Some of them when I scratch them, I can tear off the old skin and a bump appears through the opening like new skin. I would appreciate ANYTHING that you could tell me to give me some sort of relief. Also I thought I might be dehydrated so I have been eating watermelon since in contains 92% water and sparkling water, I cannot drink tap water gives me a migraine, but this has not helped either.