Is it normal to feel all of sudden tiredness,exhaustion & want to remain in bed forever and losing interest in doing anything you love to do?

Not normal,see a Dr.: No. There are many causes of fatigue.We can't diagnose you here: you need an exam and tests. Depression can cause this but there may be other issues including anemia, thyroid or other hormonal imbalances, vitamin/mineral/amino acid deficiencies,chronic infections (viral, bacterial, fungal, parasitic), environmental/food allergies,environmental toxins, sleep apnea, stress etc. Please see a good Dr.