Hi, I Have Been Very Tired For Several Months And

Hi, I have been very tired for several months and the last couple weeks have had aches in my shoulders and back, my joints in my right knee and shoulder and hip are making popping noises when I walk and stretch and I had a rash all over my body back in Feb and the drs said it was probably viral. I had night sweats and a sore throat for over a month and a half during that time. What could it be?