What is the cause of these symptoms?

Recently I have been feeling very ill, beginning with a sore throat and a headache with pressure behind the eyes. Then there was a lot of body aches, a fever as well. However, it happened very suddenly.

Also, about a week before this, my neck broke out into a itchy rash, and my arms are also a little strange, with small red dots appearing that were also itchy. I had not gotten a flu shot this year, so mainly I think it could be the flu (have got the vaccine for COVID, but still need to get tested). Is the rash unrelated, or is it possible it is related?