Hi
After hearing your history i would say chills and weakness are caused by
Lack of exercise is a common cause of fatigue, weight gain, and
muscle weakness.
Hypocalcemia is a blood condition marked by tingling, muscle spasms and aches, and confusion.
Viral syndrome is an unidentified cause of typical virus symptoms sore throat, stuffy nose, aches and more.
Exercise is vital for good health, but overdoing it can lead to muscle aches, dehydration, headache, and more.
Lyme disease is a bacterial infection spread through tick bites; symptoms include rash, fever chills, and more.
Multiple sclerosis is a disease of the nervous system causing difficulties with balance, speech, and movement.
Hypothyroidism your body functions slow down, making you gain weight and feel tired all the time.
Medication side effects include nausea, vomiting,
stomach upset, weakness, dizziness, seizures, and more.
I would advise you to do blood test for haemoglobin, calcium and
thyroid stimulating hormone test.
Regards
DR DE