I have reached a compromise with the chorus director. I'm going to drop out of the concerts that happen in less than two weeks and feature Broadway musicals. My cold symptoms have kept me away from three rehearsals. I'll attend as a member of the audience, with cough drops.
And I will plan on singing in the concerts at the beginning of June, which we will rehearse following the Broadway concerts. This takes a little pressure off of me and gives me more time to recover.