Hello! I read your question and understand your concern. I think that the symptoms you describe may be related to a possible rheumatological disorder depression. Have you measured your blood pressure ? Extreme fatigue, light headedness and fainting may be related to low blood pressure or chronic anemia. An adrenal gland insufficiency and fibromyalgia could also cause similar symptoms. I recommend you to consult with your GP and perform a routine blood test, blood electrolytes, cortisol plasma levels and closely monitor your blood pressure. Rheumatological tests ( like ANA, ANCA, ENA, sedimentation, Rheumatoid factor, etc) are necessary to exclude connective tissue disorders. Hope to have been helpful! Greetings! Dr. Aida