I began treatment with the Big 3 three weeks ago. I take them 3 days a week. Since beginning this treatment, I have experienced extreme exhaustion and a recurring headache. Initially, I panicked that this might indicate Covid 19! Thanks to all the posts I have read, it seems apparent that it is this course of treatment. In addition to the MAC, I have stage 4 metastatic lung cancer. This has made me very,very careful about staying safe from Corona spread. I am presently celebrating my 9 1/2 year anniversary of my lung cancer diagnosis. Up until now, I have had no symptoms of lung cancer or MAC. My PET scan showed some infection in my lungs which was cultured and grew MAC! I am very stressed with this tiredness. Some days, I can barely move!