Swollen Head Due To Pustules And Itchy Rashes On Head And Neck, Painful Hard Cysts Under The Skin. Possible Shingles?

Hello. For the last few months, I have been getting a very itchy rash on my head. It is mostly at the back, going down to the base of my neck.Some of the lumps were very swollen. , I tried dry-scalp shampoo, but eventually had to see my family doctor. He thought it might be eczema, so he prescribed cortisone cream. It did nothing-this is getting very bad. My whole head is swollen around the areas of the pustules. The scabs go so deep, and I can feel like a line from one to the next bunch that haven't opened up yet, under the skin. It feels like hard cysts under the skin, and these areas are so painful, sometimes I can't stand it. And to let you know, I'm on heavy painkillers, and am pretty good at handling pain. I have had chicken pox TWICE as an adult, so I thought of shingles, but I don't know. Right now, it is worst on the very back of my head. I should mention that I'm home all the time, on Disability, and lie down a lot of the time. The rash is right where my head meets my pillow. Thanks for your help.