Mycoplasma..? What do I do next?

[Folly's place]

Are you confusing MG with Marek's disease? Neither is good, but MG will be gone in three weeks or so after all the birds are eliminated (last i looked) while Marek's disease may tak a year or more (last I looked?)
Having a diagnosis will be a huge help for you, moving forward.
So sorry!
Mary