Can My Phalaenopsis be Salvaged? Mold and Black Spots on Crown (Photos)

[EvilHag]

Hi, everyone!

I'm new! I'm Angela - I just started getting into orchids and already have some issues with my first one (not a surprise). If you could weigh-in, I'd appreciate it! Trying to see if I can manage to salvage her:

I'm in California, had recently repotted this orchid in LECA pebbles inside a plastic plot with extra ventilation holes - using it as just a media, not semi-hydroponic - and have it near an East-facing window.

I got her as a gift initially and left it potted the way it most likely came from the store (in sphagmum moss, inside a foldable clear plastic cup, which was inside a clay pot). After a few months, I changed out the media into some what I now realize was not-so-good bark. I ended up cutting off almost all the roots with the exception of one aerial root and two root buds.

I was pretty bad with watering it, particularly recently as I was waiting for the LECA to arrive. I've started a routine of watering weekly (when the roots start turning silver) with the new set-up. I've only watered it once (used another pot to fill up with lukewarm tap water and pour around the plant, being careful not to get it inside the crown) since having repotted.

I started noticing some fungus growing near the crown and on some of the LECA around it, then more recently the leaves started turning yellow and have become flimsy. Lost two bottom leaves within the past week or two.

Any ideas on what went wrong? Is it too late to salvage?