Thanks for writing to Healthcare magic,
I have studied your case,
According to your symptoms I would advise you to do blood test
known as CPK-MM level of blood.
muscular dystrophy can present like such symptoms.
Also do your hormone levels in blood ,hormonal
imbalance can also present like this.
Yes you have already rule out infection and for malignancy you may need PET SCAN if some blood reports suggest similar possibility.
Hope I have answered your query. Let me know if I can assist you further.