Hello, I Have Been Experiencing Fatigue, Sensitivity To My Scalp,

Hello, I have been experiencing fatigue, sensitivity to my scalp, and recently noticed a rash forming after showers. The rash starts on my shoulders and goes down the back of my arms. I have itchy legs from inner thighs to my calves. I have had loss of appetite, not a full urine stream, and constipation at times, no diarrhea. I also have had swollen lymph nodes for a couple of weeks. Any idea of what this is?