I Have A Rash On The Back Of My Neck

I have a rash on the back of my neck both of my breast, sides, stomach and back. It has been here for several moths. I get chills and fill sick. I have a headache. My sides are starting to bruise, and the rash feels pain full at times. The rash is raised up. I have taken a steroid, and used every cream there is and used oatmeal baths and benadryl. Nothing helps