Could this be fibromyalgia

No one seems to know what is wrong with me! I have had so many blood tests and am waiting for a 24 hour heart monitor but meanwhile I feel terrible on many days. Two months ago I had a stomach infection which resolved in about a week. However, since then I am lightheaded and have pains and weakness in my lower legs and sometimes in other parts of the body, including headaches from time to time. I feel I am living in a fog physically as my head never feels totally clear. Some days I feel I am getting better only to have a bad following day. I cannot identify any triggers. All my blood tests are Ok though I do have a form of blood cancer that affects the platelets. But I have had that for 4 years and never had any symptoms, only since the stomach infection. I will have to speak to my GP again but both she and my hematology team are baffled. I realize no one here can diagnose me but just wondering if anyone else can relate.

Have you had covid by chance?

It could be fib………gia! But it could also be many other things!