I am so sorry on all what you are going through, being sick is never easy for sure...
I mentioned already in a similar post when my daughter had sore throat, sings of infection and then flare of whole body ache and joint pains. When her DR took her blood for Lyme, she said that Lyme really gets diagnosed mostly by symptoms, very rarely blood work shows Lyme disease even when patient has all the symptoms, sometime severe.
The pain/symptoms you describe can be from so many different health issues. People don't know that often strep throat test may show up positive for strep only on 3 rd time. Drs do it once and tell people they are OK, never mention to come back again if symptoms persist. It happened to me, my kids and many people I know. Only on second-third test it may come back as strep even if 2 days ago it was negative.
Mono is one of the reasons you have these symptoms, simple infection even if it didn't give you high fevers, may be a reason for it. I don't know how old you are, but if you ever survived Mono as a teen/child, your condition may be Epstein Bar now and when it flairs, give you symptoms you describe.
We can only guess here; only good DR can tell you what you suffer from.
Wishing you well