Tiredness could be due to many reasons, there are certain basic tests you should do, and do consult a Physician for further evaluation if required.
Next Steps
FBS(
fasting blood sugar), CBC(
complete blood count)-includes Hb cohnt too to rule out Anemia,PBS( Peripheral blood smear), TFT(
Thyroid function test)-rule out Hypothyroidism, do URE (urine routine test).Also as you got loss of appetite which may be due to indigestion or gastric, pancreatic, hepatic or intestinal issues, so have to check them too, do
LFT (
liver function test)and USG Abdomen and pelvis for that.
Health Tips
Drink enough water (2-3 Litres per day)include more fruits and vegetables in diet, reduce intake of sweet and oily food or junk foods, do daily exercise. Take Multivitamin (tab. Zincovit one daily after food )tablet daily for 2 months.