There is something seriously wrong with my Twinkle

[Reeses]

It started out as a black spot. I didn't think anything of it--I got a new grow-light not long ago, and i thought it had gotte a small burn. Now the spots are spreading. There are also brown spots on the pseudobulbs, and there are strange, streaky-looking patches on the leaves. None of my other 'chids is affected.

I think it might be some sort of bacterial or fungal infection, but i've never dealt with one of those before. How do I treat this?

It was also repotted recently, but l used fresh mix from repotme and I always sterilize my tools with a flame.