Have you been to the doctor yet? If you have only had this for a few days, it is probably a viral infection. There are a few things that can cause these as chronic symptoms and you would need a doctor to run some tests to see what you can find. Possibilities are Fibromyalgia, Lupus, Lyme Disease (if you have been in a Lyme endemic area), and other autoimmune possibilities.
Definitely go see your doctor. There are treatments that can help.
So very sorry you are feeling ill. How long have you had these symptoms and what have the doctors said; what tests have been done. Feeling like you had the flu and intense joint and muscle pain is something I experienced 8yrs ago. Blood tests, MRI's, etc were done and doctors, through a process of elimination, came to the conclusion that I had fibromyalgia. At that time there was no Lyrica, they gave me Zoloft 50mg. I was someone who exercised daily and felt great until then. The exercise went down to very, very, little because of the pain. It took a few weeks, but I got better. The zoloft also helped with the depression.
Wishing you well and never give up.