I Am A Singer And Have A One Woman Show

I am a singer and have a one woman show Saturday night. I have been battling a virus and now have Laryngitis. Everyone is telling me to get a steroid shot but what I am reading it may be a bad choice to mask it and sing anyway. I would cancel before I want to risk vocal damage. If when you get a steroid shot, it makes the inflammation go away, but why would it cause damage in a masking process. In that case would Advil not also be bad?