Decaying Brassavola nodosa, please help!

[Tango]

Hi everybody,

One month ago I bought a Brassavola nodosa on the Internet, and the nursery (C*****en Orchids) sent quite a miserable plant with most roots dead. I repotted it to a very airy medium (1 cm bark chunks) and now that it looked like starting to grow (very tiny and shy growths are starting to appear, see photo) 2 of the old leaves fell within the last week.

It is in a small pot with slits all around, on a shady windowsill. I water it every 3-4 days when it is already dry.

What would you do with the plant? Leave it and wait? Unpot it? Please help!

Thank you very much.