This Began 2 Weeks Ago. 1st I Had Flu Like

this began 2 weeks ago. 1st I had flu like symptoms. sore joints and muscles. no respiratory issues, weakness, no fever, mild headaches that didn't last long, they come and go. problems concentrating and problems focusing my vision. the back of my neck gets a little sore. I run out of energy quickly. no loss of appetite and no nausea. I feel pressure in my head when I am having trouble concentrating. after a week and a half the soreness in joints and muscles are gone. I think and focus a lot clearer but not entirely. neck stills gets sore at base of skull and when slightly lethargic I still feel slight pressure in my head.