Weak/achy for months. docs checked immune system in depth and hematology checked blood in depth. no deficiencies/diseases. should i be reassured?

Yes: The symptoms you are experiencing may be related to peri-menopausal status. That is a normal condition and you should not worry. For good health - Have a diet rich in fresh vegetables, fruits, whole grains, milk and milk products, nuts, beans, legumes, lentils and small amounts of lean meats. Avoid saturated fats. Exercise at least 150 minutes/week and increase the intensity of exercise gradually. Do not use tobacco, alcohol, weed or street drugs in any form. Practice safe sex.