My cortisol level has been low for the 2nd time in the morning. i received a cortisone shot in the beginning of november. would this make it low?

Cortisol: Cortisone shot from November will not affect your blood cortisol 3 months later. Presumably you are getting a cortisone shot in an affected arthritic joint? Why is a blood cortisol being measured repeatedly? Cortisol levels bounce around a lot and an isolated level means little. Does your doctor think you have Addison's disease? Maybe you should see an Endocrinologist.