Armpit, chest and inner bicep pain

I was diagnosed with Hashimoto's Disease about 2 years ago.  Recently, I have had the beginnings of joint pain in my fingers, toes and knees.  I am especially painful and stiff in my fingers in the morning.  No tests have come back positive for anything beyond my thyroid issues; but doctor prescribed Mobic.  Helped the morning pain.  In the last few months I have also started feeling "puffy" in my arm pit area (no specific lymph issues), have rib pain under my breasts (left side worse) and sides, and pain in my inner bicep area.  The pain is not severe, just uncomfortable.

Nothing has been found in any of the tests or images that have been completed.  I have high cholesterol (not treated yet), borderline high blood pressure, and the hypothyroidism.  I have seen other questions with similar symptoms, but no real answers.  At about 200 pounds and 6'-0".

Has anyone actually had these similar symptoms and received any diagnosis?  A little worried because I lost my Mom at 59 to Leukemia, and she had similar joint issues.